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Metra GMOS-04 Wiring Interface

Connect a new car stereo and retain OnStar®, the audible safety warnings and chimes, and the Bose® audio system in select GM vehicles

239 Reviews | 9 questions - 12 answers

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Item # 120GMOS04

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Overview

Our take on the Metra GMOS-04 Wiring Interface

Metra's GMOS-04 GM radio replacement interface lets you replace the factory radio in select OnStar-equipped 2000-up GM vehicles using the existing wiring and connectors. Even if you don't subscribe to OnStar, you'll need this adapter to connect an aftermarket stereo.

Metra's GMOS-04 GM radio replacement interface lets you replace the factory radio in select OnStar-equipped 2000-up GM vehicles using the existing wiring and connectors. Even if you don't subscribe to OnStar, you'll need this adapter to connect an aftermarket stereo.

Once you connect your in-dash receiver to the interface, you'll get the great sound you want, and keep these important features intact. The Bose amplified speakers and the OnStar system will operate with your new radio, as well as the door chime and audible safety warnings. This interface gives you convenient plug-in connections for the Axxess steering wheel control adapter (not included) that works with most aftermarket stereos – that means less wiring work for you.

Also, once you turn off the ignition in these GM vehicles, the factory radio continues to play until you open the door. This interface maintains that function with your new aftermarket radio. This interface is compatible with select 2000-and up GMC, Chevrolet, Oldsmobile, Cadillac, Pontiac, Isuzu, and Hummer vehicles. Warranty: 1 year.

Important Note: If you haven't done so already, please enter your vehicle information or call an Advisor at 1-888-955-6000 to find out if your GM vehicle's warning chimes are integrated with the factory radio. If so, certain warning chimes in your vehicle may be disabled by installation of an aftermarket receiver. You must use the recommended Crutchfield interface to retain the warning chimes. Failure to do so may result in serious injury or death.

Note: Most vehicles will require additional installation parts — please identify your vehicle if you haven’t done so. You can also call an Advisor for more information.

What's in the Box:

  • GMOS-04 interface module
  • 16-pin harness with stripped leads
  • 18-pin harness to 12-/24-pin GM harness with stripped leads
  • Installation Instructions
Reviews

Metra GMOS-04 Wiring Interface Reviews

Average Customer Review(s):

(239 Reviews)

Keep the factory options in your Vehicle.

Gregory from Saginaw, MI on 9/3/2017

2009 GMC Envoy
Crutchfield Customer Review (What's this?)

This is a must for any vehicle that has Onstar, other functions, and wishes to keep the factory alerts.

Pros: Doesn't degrade audio quality of aftermarket head units. Easy to install. Volume adjustment to match external amps and correct levels.

Cons: Certain side wires can be confusing, and needed if you have controls on the stirring wheel You need a tiny screw driver to adjust volume.

Harness with onstar

Anonymous from Harwich ma on 8/16/2017

2004 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

Works great. 04 silverado z71 onstar.

Pros:

Cons:

You need it so buy it.

JEFF from Gastonia, NC on 7/24/2017

2003 Chevrolet Avalanche
Crutchfield Customer Review (What's this?)

It works, and if you want everything else to you need it.

Pros: It works as it should.

Cons: A little complicated to install but help from Crutchfield it all works

Works but Wear a Helmet

Victor from Potomac, MD on 7/8/2017

2003 Chevrolet Avalanche
Crutchfield Customer Review (What's this?)

The product does EVERYTHING it needs to do BUT the installation instructions could have been much better. First-time installers may need a helmet to reduce the risk of pulling your hair out. Crutchfield and the manufacturer should consider hiring nontechnical reviewers to read the instructions from beginning to end before publication. Several of the instructions were not only nonintuitive, the were simpley incomprehensible.

Pros: -- Simple, compact module which, when property installed, does everything it is supposed to do with ease.

Cons: Installation instructions need major improvement. The good news is that Crutchfield's technical support service is worth every penny of the price and some. There were quick to get on the phone and spent all of the time needed to process through the issues.

Metra GMOS-04 Wiring Interface

William from Sacramento, CA on 6/26/2017

2004 Chevrolet Tahoe
Crutchfield Customer Review (What's this?)

Made installation a breeze. Its cool because it has the connection for the steering wheel control so you dont have to mess with the extra harness. Great product, would highly recommend. At first I was hesitant but it really was easy.

Pros: Easy installation. Has steering wheel harness included.

Cons: Harness is rather bulky

Metra GMOS-04 Wiring Interface

Bill from Parks on 6/7/2017

2004 Chevrolet Silverado 2500/3500
Crutchfield Customer Review (What's this?)

Very easy to install, only took a few minutes. works GREAT!!!

Pros:

Cons:

Exactly What I Needed

Amanda from Huntsville, AL on 6/6/2017

2004 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

Perfect fit, easy to install and is exactly what I needed

Pros: Perfect fit Easy to Install

Cons: Doesn't include antenna adapter Expensive

Metra GMOS-04 Wiring Interface

Jim from Urbana, IL on 5/30/2017

2002 Chevrolet TrailBlazer
Crutchfield Customer Review (What's this?)

I'm having trouble installing it into my 2002 trailblazer. Doesn't seem to be the right part for my install.

Pros: Still looking.

Cons: It doesn't seem to want to power the amp. Got it all hooked up but sound was very low. Spent a lot of time trying to get it figured it.

Crutchfield response on 5/30/2017 Once we saw this review, our Tech Support team reached out to Jim to issue an apology and help him further. We'll either help him get the interface working the way it should, or help him return it for an exchange or refund.

Metra GMOS-04 Wiring Interface

Anonymous from League City, TX on 5/24/2017

2003 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

Product works well, wiring instructions were terrible. Had to call tech support for help

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Anonymous from Alexandria, VA on 5/22/2017

2002 Pontiac Grand Am
Crutchfield Customer Review (What's this?)

Was perfect for my 2002 Pontiac Grand Am SE to wire up after market stereo. Simple instructions. All colors matched.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Anonymous from Thomaston, GA on 5/15/2017

2003 GMC Yukon Denali
Crutchfield Customer Review (What's this?)

Perfect

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Anonymous from lafayette, in on 4/24/2017

2004 Pontiac Grand Am
Crutchfield Customer Review (What's this?)

Easy installation for me to keep my factory harness and chimes.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Jim from Victorville California on 4/20/2017

2004 Chevrolet Suburban
Crutchfield Customer Review (What's this?)

Easy to install thanks

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Anonymous from Potosi, WI on 3/13/2017

2002 Chevrolet Monte Carlo
Crutchfield Customer Review (What's this?)

Is very easy to install. Had it all wired up in 15 minutes and works great.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Jeremy L. from Swansboro, NC on 2/21/2017

2006 Hummer H3
Crutchfield Customer Review (What's this?)

Works exactly as it should and fairly easy to install. Wouldn't expect anything less from Crutchfield.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Anonymous from Loganville, GA on 2/12/2017

2004 GMC Envoy
Crutchfield Customer Review (What's this?)

Not impressed with this instructions are not helpful at all. A lot of trial and error.

Pros:

Cons:

Buy This If You Have A Lux Bose Amp Not Pac

Jason from White Post, VA on 2/11/2017

Let me start by saying I have a 2005 Cadillac Escalade EXT with a stock Lux Bose amp and Bose speakers. You can confirm if you have the Lux Bose amp by checking for Y91 in your glove box parts list. This PAC unit was nothing but problems from the start. With everything connected properly, half the speakers would either not work or would be super quiet. The speaker fading ability is also non-existent - you lose that from factory stock. However, the Most Annoying Part of this piece of junk PAC audio unit is that it has issues triggering the Lux Bose amp on start up. Sometimes but not every time, there would be no sound when I start the truck. The Only way to fix it was to turn the truck off and back on, needless to say it was extremely annoying. The only thing I could think of to fix this was to bypass the PAC box and wire the amp directly into the stock connector but that would require cutting into my factory wires and why should I have to do that when I purchased this product? I had contacted PAC audio and you guessed it, they never emailed me back. I ended up purchasing the Metra Axxess instead. With this unit, the speakers actually function as they should, the speaker fade works, dimming is possible, last but not least there is a System Remote Control (blue) wire to hook the amp to. This finally resolved the issue with the sound sometimes not coming on with startup. The Metra costs more because the steering wheel controls are separate but boy is it worth it. It actually fun

Pros: It actually works unlike the PAC one

Cons:

Metra GMOS-04 Wiring Interface

Greg from Carlsbad, CA on 1/2/2017

2006 Chevrolet Silverado 2500/3500
Crutchfield Customer Review (What's this?)

Works perfectly!!

Pros: All inclusive of onstar and steering control. I had a few questions during the install and the service techs were awesome. It was like they were in the passenger seat. They diagnosed my goof up in less than a minute. They also gave me a tip/option idea on rear view camera wiring. Best Guys Ever!!!

Cons: Not 1!!!

Works with my Grand AM

Tim from Warner Robins, GA on 11/14/2016

2002 Pontiac Grand Am
Crutchfield Customer Review (What's this?)

Good product that does works well in my 2002 Grand Am. The only issue I have had is that the lighting dim does not seem to work with my JVC radio. I have not had time to do any fault finding as the issue could be with the car wiring, so have not marked the product on the basis of the issue. The thing stopping me giving 5 starts was the quality of the installation instructions.

Pros: Works and retains all the standard functions. Also has capacity to work with high end nav radio installations

Cons: Quality of installation instructions

Spend the $$ on this one for 04-08 Grand Prix!

John from Kewanee, IL on 10/26/2016

2004 Pontiac Grand Prix
Crutchfield Customer Review (What's this?)

Awesome! I needed this for my son's 04 Grand Prix with the Monsoon, & steering wheel controls. When I first installed the radio, I only had a $25 harness from Walmart, which listed this car as compatible. However, after installing everything the gauges would intermittently stop working. I thought this was due to voltage drop since I installed a big amp and JL 10W7 at the time. I then did the "big 3" upgrade. The gauges still would just stop working (except the speedo)... after doing some research on this issue... I learned that this GMOS-04 harness was what I needed to install. Yes it's $80 which sucks... but after making the swap with this harness... no issues with the gauges since! Money well spent!

Pros: Quality!! Works properly with 04-08 GM vehicles!

Cons: It's $80

Metra GMOS-04 Wiring Interface

Mike from Albuquerque, NM on 8/23/2016

2005 Chevrolet Tahoe
Crutchfield Customer Review (What's this?)

after some theives tried to steal my 2005 Chevy Tahoe, they broke the ignition thus shorting out my Old GMOS -04 Wiring Interface and my Radio would not work as well as my back up camera would not work . I looked up on Crutchfield this part - Metra GMOS-04 Wiring Interface. Hooked it up and "Viola" everything worked better than NEW!! I bookmarked this website so that I know where to go next time that they try and steal my Tahoe, as they are a HOT item here in Albuquerque, NM. The other thing is how easy it was to navigate thru the website to get to where I needed to go.......

Pros: Ease of installation, Better sound than before, Best Price around!

Cons: None.....

Metra GMOS-04 Wiring Interface

Mark from Mobile,al on 8/18/2016

2003 GMC Sierra Denali
Crutchfield Customer Review (What's this?)

This item was a very easy install, directions very clear!!

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Kelvin S from Norfolk, Va on 7/26/2016

2006 Chevrolet TrailBlazer EXT
Crutchfield Customer Review (What's this?)

It was suppose to make the instal plug and play, but it didn't work for me. When I pulled the radio from the console and connected an external speaker to the wires coming off the radio, it worked fine. I don't know if it's wired wrong, the factory amp is bad or all of my factory speakers are bad???

Pros: Great concept, plug and play is great.

Cons: It didn't work for me. The instructions didn't mention connecting the blue wire for amp power. Many excess wires. It's a general product for many applications and the user has to figure out which wires you need to use.

Just what I needed and an easy installation

Krist from Northern IL on 4/10/2016

2005 Buick LaCrosse

I ended up getting an incompatible GMRC-01 when I ordered everything because I didn't want to keep on-star. I thought i had done all my homework and was fairly sure my car wasn't factory amplified. Well, once installation day came, i was surprised to find it that it is factory amplified. With the GMRC-01 harness, I got this constant loud white noise hiss from all speakers even at zero volume. Thankfully, it states that you will need the GMOS-04 in the installation booklet somewhere if you have a factory amplified vehicle. Being a Saturday afternoon, I had to pick this interface up at a local big box store. I was instantly surprised by the amount of extra wires and that it already has the wiring incorporated for the steering wheel control adapter. Installation of this was a breeze and it seems to be working just fine. I only had to adjust the on-star volume on the unit I got, the other volumes were spot on.

Pros: Works well right out of the box, easy install, easy to adjust the volume levels for chimes/on-star/factory amp

Cons: GM made it necessary to use these aftermarket solutions to simply install a radio

Does its job, but hard to fit in the dash.

Phil from Omak, WA on 3/24/2016

2006 Cadillac Escalade
Crutchfield Customer Review (What's this?)

Matches up perfectly, as I would expect from a wiring interface. There are several connections I didn't use as my new head unit doesn't have Nav capability, but it's good to know they are there if a needed them. However, the combination of so many long wires and the box they all plug into made this a challenge to tuck in behind the stereo. Now that I know everything is connected right and working, I will be pulling this back out, cutting the wires shorter, tying of the ones I'm not using, and putting it back in more cleanly. Retains On-Star capability, but since my new head doesn't have a Mute wire, it powers completely off when I activate On-Star. Not a huge deal though, since I don't really use that service and it is nice to know it will still work if I need it.

Pros: Matches factory plugs perfectly. Retains On-Star and factory GPS (if new head unit has Nav capability).

Cons: Hard to fit in the dash. So many extra wires can be daunting for inexperienced installers.

Resolved the whine problem in my truck.

Paul from Tallahassee, FL on 2/16/2016

Crutchfield Customer Review (What's this?)

For years, I lived with a terrible and annoying whine in my truck. I tried all kinds of filters and radios. Once I installed this device, the problem went away. Hallelujah!

Pros: Resolved whine issues, easy to install.

Cons: None

just what I needed

Susan S. from denver, CO on 2/15/2016

2007 Hummer H3
Crutchfield Customer Review (What's this?)

Great price from Crutchfield when ordering with my new radio. Excellent customer service and tech support - helped me confirm that this was the right wiring harness for my vehicle and then spoke with Joe in tech support to review my wiring connections to make sure I wasn't missing anything. This harness looked intimidating - seemed like it had a lot of extra wires - but Joe walked me through each one and I had everything connected to the new unit in about 1/2 hour. Not too difficult even for my first time.

Pros: Wires are labeled and color coded, directions are pretty clear, tech support from Crutchfield is awesome

Cons: Looks intimidating for a novice

Noise

Matt from Birmingham, Al on 1/19/2016

2005 Hummer H2
Crutchfield Customer Review (What's this?)

As others have stated, I experienced distortion and alternator hum. Very frustrated.

Pros:

Cons:

Crutchfield response on 1/20/2016 Once we saw this review, our Tech Support team reached out to help the customer. We'll either help him get the interface working the way it should, or help him return it for an exchange or refund.

Does what it's supposed to do.

kerk from Minnesota on 10/26/2015

2003 Chevrolet Suburban
Crutchfield Customer Review (What's this?)

We don't ever really use OnStar, but it also manages other beeps toots whistles and dings, so I guess I needed it.

Pros:

Cons:

Fairly Easy

Aaron L from Tennessee on 9/27/2015

2003 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

Fairly easy to wire up and install. Also got the steering wheel adapter. The instructions for the two were a little muddy because the came separately, but some parts were duplicates. Would be much better if these could be purchased together as a kit instead of buying separate pieces. Took about an hour and a half to prewire everything to get ready to install. Followed install directions, and the unit worked seamlessly with my new radio. Only had to adjust volume slightly to get it where I wanted it.

Pros: Fairly straightforward to install

Cons: Wish it was bundled with steering wheel adapter in same box

GMOS-04

Linda from Washington on 9/22/2015

Crutchfield Customer Review (What's this?)

After 2 days of scratching our heads on why this was not working correctly, we discovered that the 18 pin connector was not seating correctly into the box (this caused the stereo to turn off and on intermittently). We had to remove and unplug the stereo again and reseat the wires in the box. Problem solved. Wasted a lot of time and mind matter over this one. Have to say Crutchfield has awesome customer service. Tech support was great.

Pros: Now that it is working it seems to be good (have only got 3 days under our belt).

Cons: Because the harness was not quality checked it cost us a bunch of time and hassle to figure out what was wrong.

GMOS-04

CA Tunes from California on 9/13/2015

2003 GMC Yukon XL
Crutchfield Customer Review (What's this?)

does as described, easy install

Pros: retains factory functions

Cons: none

Don't waste your time

JohnO from Texas on 9/11/2015

2003 Cadillac Escalade
Crutchfield Customer Review (What's this?)

My initial thoughts when I opened the package was the product was cheaply made and the plastic pieces were ill-fitting. After spending an hour soldering every wire to the aftermarket radio, I installed the radio in my vehicle. The radio powered up and I began to test the functions of the radio to make sure everything worked. There was no audio no matter what I tried. I double checked all the connections and everything was correct. I called Crutchfield and spoke with a technical advisor. He instructed me to try several different things, still with no avail. He advised he would send out a replacement and I should receive it in the next several days. I asked if there was another product available. He advised we could try the PAC5. When I received the PAC5, I was impressed with the packaging and the strict tolerances of the plastic housing. I was more impressed that all the settings are done at the factory (all I had to do was adjust 2 screws to set chime volume and set the mode for my Kenwood Radio-extremely simple to do). The GMOS-04 had numerous settings that needed to be made and still didn't work. Save yourself time and headaches...avoid the GMOS-04 at all costs. The PAC5 is a much better product and as close to plug and play as anything out there.

Pros:

Cons: Cheap Plastic Housing Too many settings that need to be done manually

Product worked as expected

TL from Pittsburgh, PA on 8/27/2015

Crutchfield Customer Review (What's this?)

This product worked well and as expected.

Pros:

Cons:

Made For An Easy Install

js from New York on 7/24/2015

2006 GMC Envoy
Crutchfield Customer Review (What's this?)

Retained all the oem features...Accessory Power,On-star,Chimes,Bose and factory amp,Had no problems with instructions and they were straight forward and very clear for my application

Pros: Retained all factory functions i needed,Made for a very easy install.

Cons: Little wire matching involved hooking radio harness to interface harness but not a big deal took 10 minutes and was well worth the time.

Had to call tech support

cielosf from New Jersey on 7/16/2015

2005 Chevrolet Corvette
Crutchfield Customer Review (What's this?)

First off I wish I had cut off at least four inches of wiring on the wires that get attached to the radio harness. When it was complete it was long and had to be wrapped and tied. I soldered the wires together and used heat shrink tubing so it came out neat and compact. If I had used crimp connectors especially the bell type there would not have been enough room to stuff all this back into the dash of a 2005 Corvette along with the GMOS-04 and relay. Had extra wires left over so I called tech support and went over everything with them to be sure all was correct . The pro's at Crutchfield were a big help. Don't hesitate if you have any doubt's as to what you are doing.

Pros: Harness works like a charm.

Cons: Certainly not plug and play.

Onstar or not Onstar?

kkrueger from Plum City, WI on 7/13/2015

2004 Pontiac Grand Am
Crutchfield Customer Review (What's this?)

Adaptor plugged right in. I was on my own with the other end of the wires... the directions were more like "general guidance". Would have preferred more specific instructions. My car (2004 Grand Am) didn't have Onstar, so I am not sure why I got a kit for "maintaining Onstar".

Pros: Plugged in on the one end...

Cons: Did I really need it for my car because I never had Onstar?

disappointed

Anthony from Dover, MN on 7/6/2015

2005 Chevrolet Impala
Crutchfield Customer Review (What's this?)

It works but is cheap had to glue it to keep together. Very cheaply made would go with pac next time

Pros: It works

Cons: It's cheap had to glue pins to gmos so all speakers stay working otherwise works but would have only paid half the price if I'd known it was that cheaply made unsatisfactory for sure

Aftermarket in 02 impala

CT from Indiana on 6/17/2015

Crutchfield Customer Review (What's this?)

Allowed me to install aftermarket stereo and keep doorchimes and other features

Pros: Allows aftermarket install without keeping factory stereo in loop (other alternative would be to keep linked to system to reset warning lights but store in trunk)

Cons: Somewhat time consuming making connections, also seems I should be able to tune stereo louder than the dial allowed

Works great but confusing

redflagharley from San Antonio on 5/31/2015

2003 Chevrolet Suburban
Crutchfield Customer Review (What's this?)

This wire kit worked great but had my head shaking for a couple of hours! I had to remove and call tech support the next day to prevent from loosing it. Turns out it was simple just not the best instructions. The kit is for GM vehicles with the Bose and onstar features. My vehicle has the Bose but not onstar. This means there are several plugs and wires on the harness that just float around not connected and not used. Drives me crazy to have all those unused connections but it works!

Pros: Value, function, and options

Cons: Instructions are horrible

Important installation component

OllieS from Longview, TX on 5/20/2015

2002 Pontiac Grand Am
Crutchfield Customer Review (What's this?)

This made the installation of the JVC KW-R710 head unit I got here happen easily. Only one hiccup in the wiring and that was easily fixed. The alert chime is much quieter then the original which I really like.

Pros: Very easy to hook up

Cons: Two wire colors are very easy to confuse.

Wiring interface

LesS from Michigan on 5/4/2015

Crutchfield Customer Review (What's this?)

Good wiring interface and the tech support is super.

Pros: Great tech support for any problems.

Cons: None

Metra GMOS-04 Wiring Interface

Anonymous from Granite City, IL on 4/12/2015

2004 Pontiac Grand Prix
Crutchfield Customer Review (What's this?)

Easy to install. Was very pleased

Pros:

Cons:

Thanks Crutchfield

JR from Iowa on 3/26/2015

2004 Pontiac Grand Prix
Crutchfield Customer Review (What's this?)

Thanks for including this with the radio. Installation was easy!

Pros: Installation was easy.

Cons: .

Metra VT-GMOS-04 Wiring Interface

Jerry K from Minnesota on 3/19/2015

2003 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

This product was extremely easy to install and use with a slight amount of technical know-how. The instructions that I got were a bit unclear (I may not have read them all) in how to splice this harness into the aftermarket radio. I ended up cutting the wires and splicing the radio harness into this. Once all was said and done, it worked really well!

Pros:

Cons:

Metra VT-GMOS-04 Wiring Interface

TKS from North Carolina on 3/11/2015

2003 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

The interface was easy to install. It was more than I needed but at least XM radio can be connected it needed in the future. All other features were transferred and work perfectly.

Pros: Everything was easy to connect and worked as advertised.

Cons: Did not need all the functions it was designed to transfer. A less functional, cheaper adapter would do the job.

Harness Installation made Easy

Jason1 from Agana, Guam on 2/28/2015

2004 Pontiac Grand Prix
Crutchfield Customer Review (What's this?)

Product was easy to work out and connect together. I would recommend carefully reading the directions just to ensure you do not connect the wrong things together. The color coding for all these units helps make it easier but just be careful. Overall very happy with the product and the ease with which to

Pros: Easy install

Cons: None so far

Easy Install

Troprice from Texas on 2/28/2015

2005 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

Installed this with my New Pioneer Navigation unit. This made for a very easy install as all the wires are color coded or are outlined in the directions. It was simple to integrate the steering wheel adapter i purchased. Everything was a simple plug and play after soldering all the wires to the units wiring harness. Works much better than the PAC Interface that was installed with previous unit, which malfunctioned for no reason after 2 years.

Pros: Simple Installation

Cons: None

Ok item

bigjohn from ga on 2/26/2015

2003 GMC Yukon XL
Crutchfield Customer Review (What's this?)

It doesn't do my door chimes all the time the right way but keeps my bose system so I'm happy

Pros: Keeps bose

Cons: Finicky with door chimes

Metra wiring device

Kim R from Chicago Illinois on 1/15/2015

2003 Chevrolet Monte Carlo
Crutchfield Customer Review (What's this?)

Just as advertised

Pros: Chime sounds cheap

Cons: Works perfectly

Metra VT-GMOS-04

Ben from Harlingen, Tx on 1/13/2015

2005 Chevrolet Tahoe
Crutchfield Customer Review (What's this?)

Installed on my 2005 Tahoe great up grade. Like everything about it. Works well

Pros: Does what it's suppose to do

Cons: None

Worth the extra Cash

John C from Arkansas on 1/10/2015

2003 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

The Metra VT-GMOS-04 Wiring Interface works as advertised. Just follow the instructions and connect the wires by color and your set. The chime and audio volume can can be adjusted to your liking. I installed it on a 2003 Chevy Silverado.

Pros:

Cons:

Best option on the market

John T from Hampton, VA on 12/29/2014

Crutchfield Customer Review (What's this?)

Best option on the market that I could find

Pros: Ease of install

Cons: none

Metra VT-GMOS-04 Wiring Interface

Anonymous from Tennessee on 12/28/2014

Crutchfield Customer Review (What's this?)

The Metra VT-GMOS-04 Wiring Interface is a great addition to add when installing a new radio.

Pros: -Clear sound and just works

Cons: -Way to many wires. -must be soldered together.

Metra GMOS-04 Wiring Interface

Anonymous from NY on 12/28/2014

2005 Chevrolet Impala
Crutchfield Customer Review (What's this?)

It works ok, I don,t use On Star so I can't comment on that part.

Pros: Ok

Cons: To many wires to hook up, directions could have been better.

Works great

Rj from Sunshine state on 11/28/2014

2004 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

I ordered the wiring interface and steering wheel adapter together. I'm glad I did they work perfectly. Everything works great.

Pros: Easy to install

Cons: None

Excellent

Brotherwind from T or C NM on 11/13/2014

2002 GMC Envoy
Crutchfield Customer Review (What's this?)

Crutchfield team was excellent. After getting wrong part from other dealer these guys cleaned that guys mess up. Works perfectly. Took but minutes to install. No problems. Rain sensors still working fine , don't use onstar but it seems like it's properly powered up. Doesn't allow all 6 speakers to function , but that's Bose's stuff. Will definitely go with these guys. Prices as good as anywhere else. Fast delivery. Even emailed me our online chat conversation which is nice so everything is open. Thanks Crutchfield...

Pros: Quick and easy install. Everything works. Quick delivery. Excellent team work.

Cons: The Bose system will not allow this harness to utilize all 6 speakers. Not their fault , it's a Bose thing I'm told by installer.

Metra GMOS-04 Wiring Interface

Anonymous from Rockland, MA 02370 on 11/11/2014

2007 Chevrolet TrailBlazer
Crutchfield Customer Review (What's this?)

Really made installation easy.

Pros:

Cons:

Didnt work

Charlie from Mt on 11/5/2014

2004 Pontiac Grand Am
Crutchfield Customer Review (What's this?)

Just spent almost $300 on new stereo and this item to make it work. Confusing to install and ended up mutilating it, so unreturnable. So now have a torn up car and down almost $300.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Bdubtex from Memphis, TN on 10/2/2014

Crutchfield Customer Review (What's this?)

Works great

Pros:

Cons:

2007 Chevy Silverado 1500 with Bose

Anonymous from Illinois on 9/26/2014

Crutchfield Customer Review (What's this?)

Used on an 07 Silverado with bose speakers and a JVC KW-R910BT head unit. Works great!! Customer Service was beyond excellent as I failed to order this with the HU but no problem. Recieved in 3 days and even got the special price, 1/2 off, that I would have recieved if I would have ordered both together, instead of being charged full price. :-)

Pros: Everything!

Cons: None

Perfect interface for my Suburban

Paul from Houston, TX on 9/24/2014

2004 Chevrolet Suburban
Crutchfield Customer Review (What's this?)

It works and easy to install.

Pros:

Cons:

Metra VT-GMOS-04

Jorge from Haines City, Florida on 9/19/2014

2006 Chevrolet Corvette
Crutchfield Customer Review (What's this?)

Plug and play, no issues

Pros:

Cons: Too bulky

Good Product

DCP from Houston, TX on 9/2/2014

Crutchfield Customer Review (What's this?)

This product is a bit intimidating to look at, but the instructions are reasonably clear and it works as advertised for what I am doing with it. I am using it only to connect to a Bose amp. I cannot comment on the other functions.

Pros: Facilitates an aftermarket head unit to a Bose amp. Sets itself up. Unlike competitive product, it allows the fader to work.

Cons: Bulky with a lot of wire to move out of the way during installation.

Metra VT-GMOS-04 Wiring Interface

KellyK from Georgetown, Tx on 8/28/2014

2006 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

Wiring harness works great. The wiring instructions were easy to understand. My only complaint is that there needs to be some additional info on using the ASWC interface.

Pros: Clear and concise wiring instructions.

Cons: Needs additional elaboration about using the ASWC interface with it.

Metra GMOS-04 Wiring Interface

Anonymous from Roanoke Va on 8/6/2014

Crutchfield Customer Review (What's this?)

Was not a good unit

Pros:

Cons:

5 stars!

Wyatt from Edgerton, MN on 8/2/2014

2004 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

Great purchase, easy install and lives up to its perks!

Pros: Easy install

Cons:

Wiring harness

MikeH from Tulia, TX on 7/26/2014

Crutchfield Customer Review (What's this?)

Works very good in 2004 Silverado 1500

Pros: Easy to install

Cons: Too many red wires and no explanation which one goes to what.

GMOS-04 adapter cable

zbee062 from Anderson, SC on 7/22/2014

2008 Chevrolet Corvette
Crutchfield Customer Review (What's this?)

I recently purchased a DNX890HD to replace an older unit in a 2008 non-Bose Corvette. The instructions were reasonably clear and I successfully spliced the adapter and the 890 unit together and everything worked first time. This included rear and forward facing cameras, OnStar (no subscription but music correctly muted automatically while listening to the recorded message). The nav screen automatically switched to the rear facing view when reverse was selected. The HD radio worked very well, as did an iPod, an MP3 player (via the Kenwood KCA-IP202 cable) and an iPhone 4S via the 890 built in Bluetooth system. The speakers could be controlled as per input to the 890 unit. Chimes worked correctly when the door was opened in accessory mode. Did not test other possible alerts. Had to read instructions closely several times to catch that the GMOS-04 cable red wire connects to the red wireS (i.e. both?) from the 890 unit. Including the word "both" red wires would have saved some time trying to understand which red wire to use. Per comments below one red wire should be connected to the steering wheel controls which was not used on this installation.

Pros: Instructions were good and easy to follow. I found it useful to read other reviews in various forums before splicing the cable to gain a better understanding of any potential problems that may arise (there were none for me).

Cons: None except it looks a mess when everything is connected, but that is hidden from view when installed. Only tested for one day in the car as the Nav system failed ("no maps available") , nothing to do with the cable but it prevented longer term testing as the 890 unit was returned.

Metra GMOS-04 Wiring Interface

Anonymous from Lexington, Kentucky on 7/14/2014

2004 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

Very complicated with poor instructions

Pros:

Cons:

Nice unit

Anonymous from Lincoln Ne on 7/1/2014

2005 Chevrolet Avalanche
Crutchfield Customer Review (What's this?)

Straight forward wiring

Pros:

Cons:

Does what it's supposed to do...

S from Kansas City on 6/3/2014

2002 GMC Envoy
Crutchfield Customer Review (What's this?)

Works perfectly in my 2002 GMC Envoy.

Pros:

Cons:

Works with a little intervention.

Allen E. from Oswego, IL on 4/28/2014

2002 Chevrolet Monte Carlo
Crutchfield Customer Review (What's this?)

Not a difficult install if you can handle a soldering iron and read. Unfortunately the directions were not 100% accurate. Probably i the nature of a "universal" adaptor. Had to experiment a little with the wires that were supposedly "not used". Head unit didn't receive power at first after follwoing teheir instructions. Turned out that the three wires that were to be "cut" and not used, 2 had to be reconnected for the head unit to function. So far works fine . . . with a little ingenuity on my part.

Pros: Works.

Cons: Not perfect instructions

Metra GMOS-04 Wiring Interface

Anonymous from sonora, Tx on 4/21/2014

2003 Chevrolet Tahoe
Crutchfield Customer Review (What's this?)

It works good, it does what it supposed to. The only concern I had was during installation there were two bat. Red wires, now were both of those wires supposed to be connected together or was just one supposed to be connected. I connected both of them together to the12v source wire. Should I leave both of them connected or go back in there and just leave one connected?

Pros:

Cons:

Crutchfield response on 4/23/2014 One of those red wires is meant for powering the optional ASWC-1 adapter for the steering wheel controls. Our tech support team followed up with the customer to let him know.

Easy install... Easy life

MisterBond1989 from Adelanto on 4/10/2014

2003 Pontiac Grand Am
Crutchfield Customer Review (What's this?)

This adaptor is awesome! Makes things easy to install another radio. No cutting or splicing of wires. Only one issue that I have found while using this product is that the factory Monsoon amp in the 1999-2005 Pontiac Grand Am does not get bypassed. If you have a Monsoon equipped Grand Am; the factory external amp needs to be used in order for the factory speakers to work. This makes sound quality very poor and low. If this is the case for you, I suggest installing an external amp and get rid of the Monsoon amp. Beside that issue; great product!

Pros: Makes install of radio easy, clean, and worry free. No cutting of the factory wires needed.

Cons: Does not bypass Monsoon amp in the 1999-2005 Pontiac Grand Am.

Does it's job

JYaz from Hanover, PA on 4/10/2014

2005 GMC Sierra 2500/3500
Crutchfield Customer Review (What's this?)

It does what it should

Pros: It works

Cons: All of the wires are confusing. Instructions aren't the best.

05 gmc truck upgrade

Doug H from Charleston S.C. on 3/25/2014

Crutchfield Customer Review (What's this?)

Upgrading the truck with a sony cd player,truck has the bose radio speaker system,and the connections were spot on,cant imagine how much better the truck sounds now,that i have a real radio in it

Pros: easy to install,ajustable door chime module

Cons: blue/white wire for amp signal looks alot like the blue/pink wire,that should be pinker,or not even blue at all

Great adapter

David from Fremont, NC on 3/9/2014

Crutchfield Customer Review (What's this?)

Easy install and worked great with my 2005 Avalanche with Onstar,Bose Sound System and Navigation. You may want to shorten the wires on the 16 pin connector unless you have plenty of room for the wires and your new stero.

Pros: installs quickly and instructions are very clear and easy to follow. Crutchfield support was extremely helpful but you shouldn't need them with this adapter. I had issues with another adapter not working with my vehicle and required their help.

Cons: None

Simple

Dahveed18 from Flint, MI on 3/9/2014

2005 Pontiac Grand Prix
Crutchfield Customer Review (What's this?)

Simple to use!

Pros: Adjustable gain, adjustable OnStar volume, adjustable chime level

Cons: None

Metra VT-GMOS-04

Sean P from Southern California on 2/22/2014

2005 Chevrolet Avalanche
Crutchfield Customer Review (What's this?)

Plug and Play, worked well

Pros: easy install

Cons: needs second cable for steering wheel

Worked well

CCVirginia from Fairfax, VA on 2/18/2014

Crutchfield Customer Review (What's this?)

Worked well to integrate with a 2005 Suburban. Retained all the factory functions.

Pros:

Cons:

Works

aditaa from Austin, TX on 2/8/2014

2005 Chevrolet Silverado 2500/3500
Crutchfield Customer Review (What's this?)

Works as expected

Pros: factory amp works onstar and door chimes still work via radio speakers

Cons: very messy wiring configuration still need extra part for steering wheel controls

Worked perfect

Lox4rox from Texas on 2/2/2014

2004 GMC Yukon XL Denali
Crutchfield Customer Review (What's this?)

Worked perfect with my 2004 Denali. Plug and play once the harnesses are wired up...instructions were excellent. All onstage and chimes at just as with factory head unit.

Pros: Easy if install. Everything works per factory norms.

Cons: None

Does what it says it'll do

JT from Bosque Farms, NM on 1/25/2014

2003 Chevrolet Silverado 2500/3500
Crutchfield Customer Review (What's this?)

Easy to install, works as advertised. Like the fact that I can turn the door chime way down.

Pros: Ease of installation, good instructions

Cons: None so far

Works well

Jeff M from San Antonio, TX on 1/3/2014

2003 Chevrolet Suburban
Crutchfield Customer Review (What's this?)

This unit was necessary to retain the door chimes and the Bose system in my truck. My truck isn't equipped with OnStar, but this unit will accommodate those vehicles that do. I would prefer not to have the extra wires floating around the dash, but for the price, I'll live with that. I had a couple of questions on the install, but as always, Crutchfield customer service was able to answer them quickly and the install was a breeze.

Pros:

Cons:

Unit works, instructions horrible

Steve KY from Ashland KY on 1/3/2014

Crutchfield Customer Review (What's this?)

First of all, the thing does what is supposed to. The instructions are miserable. Hook up red wire,it has two. several others are the same way. I called Crutchfield and they told me how to make it work. Without that it would ne impossible.

Pros: Works

Cons: Have to call to get help, not so good when trying to install Christmas present on Christmas day.

Works well

Matt from Milwaukee, WI on 1/3/2014

2006 GMC Sierra 1500
Crutchfield Customer Review (What's this?)

Works as its intended, Instructions could be a bit clearer though.

Pros: Adjustable chime volume

Cons: n/a

Metra GMOS-04 Wiring Interface

Anonymous from Lansing, Mi on 12/22/2013

2003 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

Very easy and clear instructions, everything worked and made sense. Potentiometer was a great but unadvertised bonus.

Pros:

Cons:

Perfect for GM with Bose

EA from El Segundo CA on 12/19/2013

Crutchfield Customer Review (What's this?)

Works perfectly. Easy to install

Pros: Works perfectly. Easy to install

Cons: None

Hope the new version is better than the old

Ross from Chesapeake, VA on 12/13/2013

Crutchfield Customer Review (What's this?)

I had the exact same adapter previously installed in my 2003 silverado SS. After about 4 years my battery died out of no where - after months of trying to diagnose the issue and finally taking it to a stereo shop they found this adapter to be the cause of a 754ma draw. I recently purchased this one and it solved the issue. After reading online this it apparently a common issue but since no other adapter is out there you're pretty much out of luck if you want to keep BOSE and chimes with an aftermarket HU. That aside - the instructions are great - install is painless assuming you know how to strip and crimp wires. The overall bulk added to the harness is extremely annoying but again, what other choice do you have? Fingers Crossed this unit works.

Pros: Easy Installation, Good instructions

Cons: Overpriced, does not last, bulky mess added to your oem harness

Simple and easy to install

Drock77 from Claremore, Ok on 12/3/2013

Crutchfield Customer Review (What's this?)

Simple to wire up and easy to install

Pros: Simple to wire up and easy to install, it also has a volume knob to increase or decrease the vehicle chime volume.

Cons: N/A

Metra GMOS-04 Wiring Interface

Anonymous from Aurora IL. on 11/30/2013

2001 Pontiac Grand Am
Crutchfield Customer Review (What's this?)

Works well, only reason I gave a 4 is because we had to call for wiring issue, it is a bit universal which I understand. the good news is the staff is great, always answer the phone and talk you through it.

Pros:

Cons:

great quality product.

richie o. from bronx ny on 11/23/2013

2006 Chevrolet TrailBlazer
Crutchfield Customer Review (What's this?)

Great Product. harness works like factory with newer modern cars. Love the web site.very helpfull. cant wait to do more business

Pros: Crutchfield knows there stuff

Cons: None

Pure awesomeness

jasonsfn from Sacramento, CA on 11/17/2013

Crutchfield Customer Review (What's this?)

Being able to install an top of the line Alpine and also have it integrate with all of my factory equipment on my 2004 Tahoe was amazing, this wiring kit is a must! would use it again in any applicable install situation.

Pros: Allows you to keep all of the things you loved about the factory receiver and on star while upgrading your sound. It works and sounds amazing. even has open slot for the steering wheel harness to plug right in saving time and the use of extra wiring.

Cons: Cant really find any.

A Must Have

Anonymous from Sussex, WI on 11/7/2013

2006 GMC Envoy
Crutchfield Customer Review (What's this?)

This is a must have ... It was very easy to hook up and works great. I would strongly recommend this to anyone hooking up an aftermarket radio.

Pros: Easy to hook up and as always the customer support is the BEST

Cons: Bigger print and a easier to read diagram

It just works.

Dirk A from Jonesboro, AR on 11/6/2013

2008 Pontiac Grand Prix
Crutchfield Customer Review (What's this?)

Ok....first off I have been hesitant about upgrading the head unit it my last few GM vehicles due to interface issues. With a 2008 Grand Prix that is not going anywhere, and no way to use any external devices decided it was time to upgrade. Our car has the factory amp with the "Monsoon" system, and I was pretty sure that I would have to bypass it. After reading the capabilities of this integration adapter......it seemed I could retain the amp, which would simplify installation. It did this perfectly, along with the retention of the factory chimes. The device itself is just a small black box, with 2 wiring harness. It "inlines" between the head unit and the factory plugs. I did not have to adjust the volume level for either the OnStar, the chimes, or the speakers. This procedure if needed is described in much better detail on the manufactures website. THIS IS IMPORTANT!! If like me, you tested everything before buttoning it back up, the chimes for the "key in ignition", lights on, door open, etc. DID NOT WORK until I plugged the Driver Information Center (DIC) back up. At first I thought it was a problem with my wiring or the Metra unit, but since I couldn't leave the car apart....I went ahead and put it all back together.....everything worked as needed after the DIC was plugged back up. If Metra could have kept the steering wheel controls and kept the date display on the DIC, the unit would have been perfect.

Pros: Simple instal, works as needed, good build quality.

Cons: High MSRP, some features could be added, poor included instruction.

As if it were factory

Ray S from Sandwich Il on 11/3/2013

2003 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

I fairly strait forward wiring job works great.

Pros: A quick download of a PDF from the web site and it was a breeze

Cons:

Metra VT-GMOS-04 Factory Integration Adapter

Jack from Castro Valley, CA on 10/31/2013

2005 Pontiac Grand Am
Crutchfield Customer Review (What's this?)

After installing this unit in my 2005 Grand Am GT soldering every connection and using heat shrink. I had nothing but problems. I double and triple checked the wiring all was correct. I had low volume even after using the adjustment knob. (it did nothing) The sound only worked with the door open and chimes ringing. close the door and no sound but the radio still had power. I called Cructhfield tech. The tech person was very nice and tried to help but even after I tried all the things he suggested nothing changed. So I removed the unit and installed a GMOS-01 similar to the 04 but without the BOSE feature. I don't have BOSE in this car so I really didn't need the 04 version anyway. So now all is well.

Pros: None for me.

Cons: Did not work. I had to cut all those beautiful connections I made.

Crutchfield response on 11/3/2013 We forwarded this review to our Technical Support team for follow-up. Lifetime tech support comes with every Crutchfield purchase.

Metra VT-GMOS-04 Factory Integration Adapter

Mike F from Fort Worth, TX on 10/28/2013

2003 Buick Rendezvous
Crutchfield Customer Review (What's this?)

Kept my door chimes and OnStar integrated on my 2003 Buick Rendezvous. FYI, READ ALL INSTRUCTIONS!! I didn't read where you are supposed to set the gain on the harness. I thought my newly purchased JVC bluetooth unit was a terrible buy for the 1st few days. Then, I went back and read all the instructions on the Metra integration adapter. Opened the dash back up and set the gain. Made ALL the difference. Speakers are rocking once again!

Pros: Keep integration

Cons: Some of the wiring instructions aren't exactly clear, but managed to get it figured out without too much hassle.

good adapter

chefjoey from woodridge, il on 10/26/2013

2005 Chevrolet TrailBlazer
Crutchfield Customer Review (What's this?)

needed this to install aftermarket radio in my 2005 trailblazer with onstar, satellite radio, and factory chimes

Pros: works ok

Cons: wiring instructions do not cover all the wires that are on the harness, hard to adjust the volume for the onstar, need to pull the radio !

Great product keeps the bells and whistles in your automobile.

Pasquale M. from Massachusetts on 10/24/2013

2008 Hummer H3
Crutchfield Customer Review (What's this?)

If you want to keep your car/truck factory with the bells and whistles this item is a must. Easy install.

Pros: Easy install just follow the directions. Others have said that this install created a battery drain. Only way that will happen is if you cross your power line (red) with the memory line (orange). A perfect solution to keeping on star and door chimes on your vehicle. Super easy to install with you after market radio.

Cons: None

Metra GMOS-04 Wiring Interface

DarrellD from San Antonio, TX on 10/11/2013

Crutchfield Customer Review (What's this?)

This harness worked flawlessly

Pros:

Cons:

Metra GMOS-04 Wiring Interface

d500 from Independence, KY on 10/2/2013

2004 Chevrolet Avalanche
Crutchfield Customer Review (What's this?)

Its a nightmare to get hooked up but it works very well when you finally figure out the directions

Pros:

Cons:

Worked right out of the box.

Trevor from Albert Lea, MN on 9/16/2013

Crutchfield Customer Review (What's this?)

There are extra instructions on the Metra website that does not show up with the unit, but everything installed without a hitch. You need to set the door chime first with the adjustment screw and then use the same screw to adjust the volume of the head unit, this is the part that is on the website.

Pros: Worked flawless

Cons: Price, directions not complete.

Metra VT-GMOS-04

Steve D from California on 9/5/2013

2003 GMC Sierra 2500/3500
Crutchfield Customer Review (What's this?)

This adaptor works perfectly! I used this to install a Kenwood DDx470 in my 2003 GMC 2500HD. The directions were well written and easy to follow. Everything works as it should. I also used the steering wheel controls adaptor. The pre-wired connectors make it simple to install.

Pros: Easy to follow instructions.

Cons: None. Everything worked perfectly.

Metra VT-GMOS-04 for GM Vehicles

JimM from Greenville, NC on 9/3/2013

2006 Chevrolet Corvette
Crutchfield Customer Review (What's this?)

Used this adapter to connect a Kenwood HD with Nav system into a 2006 Corvette. The connections are very well explained into the instruction and wire color code matched very well with the wire of the Metro adapter. This made it very easy for myself to install. The only issue was the instruction for corvettes(only) indicated the adapter needed to be attached to a relay. The instruction should note that the relay is not on the car and would need to be purchased and installed using a fuse tap. In all it went very well as it worked without having to make any adjustments or corrections.

Pros: Color codes on wire matched codes on the Kenwood radio

Cons: Bulky wire pack to place behind the radio.

Great product

Anonymous from Lutz florida on 8/29/2013

2004 Cadillac Escalade
Crutchfield Customer Review (What's this?)

Great part thank Crutchfield

Pros: Easy installation

Cons: Non

Metra GMOS-04 Wiring Interface

Anonymous from Franklin, Tn on 8/22/2013

2003 GMC Envoy
Crutchfield Customer Review (What's this?)

Works great the only thing is in the instructions it says the knob it for chime volume. it's not it controls the amp volume

Pros:

Cons:

Integration Kit

Awt2b! from Seattle, WA on 8/12/2013

Crutchfield Customer Review (What's this?)

I used this harness for our 08 TrailBlazer SS to replace the Bose with a Kenwood. Everything I needed was included. There is no reason not to buy it from Crutchfield...It was a lot more money at any other place I looked!!

Pros:

Cons: For the Bose/OnStar there is a BabyBlue wire that you need to hook up for the proper sound to work. Then on the 'inline' box that comes with the kit...It has a small blue adjustment knob that we did not see until after we hooked up the blue wire to get sound. Then we turned the blue adjuster clockwise and UP went the volume...make sure your Deck is on about volume 2 when turning up the blue dial.

Worked great but still took work

Soldier meister from Pasadena, CA on 7/26/2013

2004 Chevrolet Suburban
Crutchfield Customer Review (What's this?)

Worked great! Wires colors matched and everything. I soldiered the connections so it took a little longer. Note, when connecting the steering control adapter you the 12pin connected to this not the 12pin that comes with the steering wheel controls adapter.

Pros: Works great

Cons: Lots of wires - would be awesome if it used quick connects.

Current replacement interface for GM trucks

Angelo from Virginia Beach, VA on 7/23/2013

My old interface was on its way out, I had an alpine deck in my 2004 Sierra 2500 HD for almost 6 years from Crutchfield, so I called them and they sent this interface for half price to replace it. Shipping and customer service as always is A++ with these guys, but the interface itself is as expected from anything made in China....less than sub par. The wiring was fine, soldered everything into place, the box (interface) itself was a dud, so after running the gambit of troubleshooting, I called up Crutchfield and they sent me a replacement for free with a pre-paid return via UPS. The second one worked fine, I really appreciate all the years of great support guys.

Pros: Easy install with a bit of common sense and the right tools, supports a wide variety of GM vehicles.

Cons: Made in China and is junk....but since it's the only reasonable option to run aftermarket radios in GM trucks.....

Do not buy this product!

Joe S. from Lowell, MI on 7/13/2013

2001 Chevrolet Monte Carlo
Crutchfield Customer Review (What's this?)

Do not buy this adapter unless you plan to leave your car connected to a battery charger every night. Within two days of installing this, my battery was completely dead. I fully charged the battery, and it died again within two days. I had the battery tested, and it was fine. This is the second GMOS unit I've installed that has caused this problem, and yes...it was installed correctly. Not that the instructions are particularly well written, but the wire connections are not that complicated. I ended up removing the GMOS unit and just keeping the wiring harness from it to connect to the vehicle's wiring harness...and surprise...the problem is gone. Ultimately I lost my OnStar (which I don't use) and my door chimes (who cares). It sucks that I had to pay this much for a $5 wiring harness, but that's what I get for not reading all of the reviews. It turns out many people have had the same issue with this unit. Crutchfield should realize this unit is junk and stop telling people its "required"...it most certainly is not, and it will cause you nothing but headaches. If I could have given this thing less than 1 star, I would have.

Pros: Easy to connect, maintains door chimes and OnStar. It also allows you to make good use of a battery charger and makes you late for work until you pull it out. The only useful part of it is the harness that connects to your car's factory harness.

Cons: Seriously diminishes the sound to your speakers and drains your battery when the car is off.

Metra GMOS-04 Wiring Interface

Anonymous from Indianapolis, IN on 7/12/2013

2002 GMC Envoy
Crutchfield Customer Review (What's this?)

Product worked as desired. Resolved issue with another radio that I bought, and no sound would play after it was installed. Returned that radio, bought new radio from here, with this adapter and all is working we. The real issue was the wiring, and I called support twice. Waited just a few minutes each time and they were able to resolve my problem in just a few minutes..

Pros: Crutchfield support was awesome

Cons: None

Easy install.

Michael from Independence,MO on 7/10/2013

2006 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

Easy install, unless you have Bose. Had to retire Bose amp in center console to bypass it. Not bad. You will have to bypass Metra module with your speaker leads if getting rid of Bose amp. Then run wires for right front speaker coming out of module to input on Bose amp right front. The from output right front on Bose amp to parrot speaker you have to install under cup holder. Works like a charm this way.

Pros: Easy to install. Easy to adjust.

Cons: Need additional speaker to hear warning chimes and OnStar and must bypass factory amp to get the most out of your new stereo.

Metra GMOS-04 Wiring Interface

Anonymous from Gilberts, IL on 7/8/2013

2005 Pontiac Grand Prix
Crutchfield Customer Review (What's this?)

Perfect, couldn't work better

Pros: Great instructions and labeling

Cons:

GMOS-04

T from Litchfield, IL on 6/24/2013

Crutchfield Customer Review (What's this?)

What ever you do, try everything before putting your dash back together. Had to bypass hooking my parking brake wire to the lt. green wire of the gmos-04. If these are supposed to be vehicle specific they need to work on them some more. Thanks to the crutchfield techs they are the best. Only had one that wasn't much help but call the guy that helped me the most. Thanks Casey

Pros: easy to hook up

Cons: extra wires again and a pain to try and put them behind the radio in the dash neatly.

GMOS-4

Nick from Houston, Tx on 6/22/2013

Crutchfield Customer Review (What's this?)

A-

Pros: Retained all factor and Onstar chimes as promised.

Cons: Loss of stock amplifier but system is upgradable due to aftermarket radio.

Works OK

LBRU from Falls Church, VA on 5/27/2013

Crutchfield Customer Review (What's this?)

Works fine

Pros: Easy installation

Cons: None

simple, sounds good.

billy from auxvasse mo on 5/25/2013

2004 Chevrolet Avalanche
Crutchfield Customer Review (What's this?)

simple, works great.

Pros: easy to install. works.

Cons: having to buy to begin with.

Perfect replacement for GM09SR interface

Angelo from Va Beach, VA on 5/14/2013

Crutchfield Customer Review (What's this?)

I had an Alpine 500CDA9856 deck in my 2004 GMC sierra, the old interface blew (it was a Scoshe GM09SR). I called up Crutchfield after almost 5 years of having the radio, and they walked me through the troubleshooting and gave me this new interface at half off. It arrived in 2 business days UPS ground, was relatively easy to install, the instructions were clear and the colors of the wires all match with my radio's harness. With a wire strippers, soldering iron, and tape and a little G2, you'll be able to get this wired up in no time. If all else fails, their tech support is on standby and willing to help, the simple fact that their techs answer the phone even at 9pm and have the answer to my issues even after five years has made me a lifetime customer.

Pros: Easy to install, made in USA.

Cons: N/A

Works Great,, Kepy My Factory Chimes, and Bose System.

Bruce from Chicago, Il. on 5/8/2013

2004 GMC Yukon
Crutchfield Customer Review (What's this?)

The GMOS-04 works very well, and I was able to keep my chimes, and use my current Bose Speaker System. Follow the directions, and if you have a problem, you can call tech support and they will talk you through it. All the wires are color matched, and simple to put together, If the chimes are too loud for your taste, the volume is adjustable. Forget about the bad reviews, and get this unit if you have chimes and a Bose Speaker System. You can also add a steering wheel control mudule as well if you desire. I decided I did not need it because my Head Unit came with a remote, so I am sastified. Great product, and Crutchfield sells it for half price with a purchased radio. Great Deal!!!

Pros: Works great at factory setting, if connected as directed.

Cons: None.

Adapters are a must for easy install

Matthew from Minnesota on 5/7/2013

2004 GMC Yukon XL
Crutchfield Customer Review (What's this?)

As much as I try to "save" money, these adapters are absolutely necessary to help retain your sanity - they make the installation of any stereo that much easier... I'm just glad they give us 50 percent off when we purchase it with the system! Read people had problems with some units - no problem with ours.

Pros: Makes installation 5000 times easier and faster!

Cons: Adds a little expense to your project (but worth it!)

great

LAURAcr125 from palmdale, CA on 4/22/2013

Crutchfield Customer Review (What's this?)

I missed my Pioneer!

Pros:

Cons:

Good product

Anonymous from Lexington, SC on 4/17/2013

Crutchfield Customer Review (What's this?)

I am not a wiring expert. So the wiring could some how be made simpler like a website that matches all aspects together to tell you which wires to use and which wires you won't be using

Pros: Works good

Cons: Wiring instructions could be made simpler

ok

Anonymous from DSM on 3/25/2013

2001 Pontiac Grand Am
Crutchfield Customer Review (What's this?)

took two unit to get it to work on my 01 grand am

Pros:

Cons:

low sound/ crappy highs

alex from germany on 3/15/2013

2004 Chevrolet Impala
Crutchfield Customer Review (What's this?)

it works but, i still am having trouble with my front speakers the quality of sound is unacceptable..

Pros: chimes

Cons: crappy sound from front speakers you have to increase the volume and it becomes distorted

Hopefully second one works better than first!

Anonymous from Buffalo, MO on 2/26/2013

2004 Chevrolet Monte Carlo
Crutchfield Customer Review (What's this?)

I had a factory stereo and Bose system and replaced stereo with a Pioneer AVH3400. After getting everything hooked up, it didnt seem to be near as good as my factory stereo which sounded awesome. The only reason I replaced the stereo was I wanted blutooth and ipod controls. Once installed, I'm getting virtually no sound from front speakers. I jumped around GMOS unit with front speaker wires (per Crutchfield tech support) and they sounded great. Credit Crutchfield for doing a great job helping determine the issue and trying to resolve it. We'll see when the replacment unit gets here. If it doesnt work, I'm just gonna bypass the speaker hookups on this thing.

Pros:

Cons:

JUNK JUNK JUNK

Joshua from Twin Cities, MN on 2/7/2013

2004 Pontiac Grand Prix
Crutchfield Customer Review (What's this?)

I'm trying to install this GMOS-04 in a 2004 Grand Prix GTP, and the new interface makes my speakers pop when I turn the key from off to acc/on. Or when I open/close the door under certain situations. I've been on the phone with crutchfield at least 15 times to find a work around, and nothing. (Not their fault, this is a crappy product). After looking around online, and reading other forums and threads, I can see that I'm not the only one. It's still not fixed right now.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Anonymous from Moultrie, GA on 2/5/2013

2003 Chevrolet Impala
Crutchfield Customer Review (What's this?)

Great

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Terrance from Church Point, La on 1/23/2013

2006 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

I like that I can still use with my bose speakers and still have OnStar. The installers had a hard time getting the door chimes to work. I sometimes wish that part didnt work because the volume of the chimes is to loud.

Pros: Still able to use OnStar and have bose speakers

Cons: Door chimes is to loud. Compared to before Id say its 10xs louder. Which is not something I want to hear everytime I turn on truck or open door. I really hate that it's so loud!!!! Can you lower the volume??

Crutchfield response on 1/23/2013 We forwarded this review to our Technical Support team for follow-up. Lifetime tech support comes with every Crutchfield purchase.

Metra GMOS-04 Wiring Interface

josh from pleasant view,tn on 1/5/2013

2005 Chevrolet TrailBlazer
Crutchfield Customer Review (What's this?)

got as a Christmas gift from parents, they ordered the wrong part, was able to return for correct one with even trade and postage paid return, my dad and i installed it in a few hours

Pros:

Cons:

gmos-04

keith from groveport ,ohio on 12/25/2012

Crutchfield Customer Review (What's this?)

Great product,excellent tech support department.Thumbs' up for you guys.

Pros:

Cons:

No Steering Wheel Control

B.L. from Columbus, OH on 8/15/2012

2004 GMC Envoy
Crutchfield Customer Review (What's this?)

Very disappointed that I lost my steering wheel controls. The product info is correct except for that one issue. Installers said I needed an additional component, so I opted not to. Maybe just an installation error, but future purchasers should doulble check.

Pros:

Cons:

Almost perfect

Greg D. from Kansas City, MO on 8/2/2012

2004 Hummer H2
Crutchfield Customer Review (What's this?)

The instructions are very clear (except as some other reviewers have pointed out there are two red wires not the one mentioned in the instructions.) The only down side about it was my steering wheel controls are not doing anything after I did the install and that is one feature said to be maintained by the use of this device.

Pros: You can maintain your onstar and chimes when moving to an upgraded stereo.

Cons: Didn't maintain the steering wheel controls as advertised.

GM adapter

stevem from fl on 7/27/2012

Crutchfield Customer Review (What's this?)

Works great, take your time and read directions a couple times before wiring. Put it in an 04 Chevy 3500.

Pros: Keeps all factory chimes. allows volume adjustment for chimes.

Cons: A lot of wiring and soldering. If you don't have any experience I would suggest a professional.

Works as advertised, not too bad to install

oTurtlez from Scituate, RI on 7/12/2012

2006 Hummer H3
Crutchfield Customer Review (What's this?)

The installation wasn't nearly as bad as I had anticipated. I just soldered the matching wires, and taped them up and it was good to go. The chime is close enough to the stock one, and my head unit works fine. If I need to buy a new head unit for another GM vehicle, I won't hesitate purchasing another GMOS.

Pros:

Cons:

Weak point of installation

coachabk from Lake Jackson, Texas on 7/4/2012

2003 Chevrolet Avalanche
Crutchfield Customer Review (What's this?)

Installed this in my '03 Chevy Avalanche. The instructions, as many others have stated, could use some improvement. If I were just installing this harness without the steering wheel control adapter, things would have gone fairly smoothly. However, I had to call Tech Support with a few questions along the was because there is a portion of the harness that looks real similar to the steering wheel control adapter that isn't used. I do which that the harness included a connection to the headlamp circuit that would have allowed the display to dim when the headlamps were activated.

Pros: Plug and play.

Cons: A bit confusing on wiring; no dimmer circuit.

Slow and Unsteady loses the race

Cd from Anniston AL on 6/21/2012

2006 Chevrolet TrailBlazer EXT
Crutchfield Customer Review (What's this?)

The GMOS for the most part provides an easy interface overall. However, it slows some feedback to the head unit down. Our install was going great till we encountered problems with the parking brake safety, etc. We later determined it was a result of the GMOS being slower than what the head unit was looking for. It's an overall necessity for GM vehicles, but can hinder your install time.

Pros: Makes getting started easy.

Cons: Slow feedback to head unit can paralyze some features

GM Factory Integration Adapter

sid from schenectady, ny on 6/3/2012

2004 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

I Have installed many decks over the years, thats why i decided to try this my self. The only Issue i had was that most decks have a constant power, ignition power and a ground. The basic 3 wires that have to be hooked up, on the side that hooks to the deck there was 2 Ignition (red) wires. this was a little confusing the instal manual did not say weather to hook up both red wires to the deck ignition. I did anyway and it worked fine. this issue may need to be looked into. it was easy for me because of my history. but for somebody else may not be.

Pros: Easy install

Cons: need to be clearer on install.

GM factory intergation Adapter

Tyson from queens NY on 6/1/2012

2003 Cadillac Escalade ESV
Crutchfield Customer Review (What's this?)

just what I needed works perfect my radio sounds even louder than before with my same bose system in my cadillac but with a aftermarket radio I still have onstar and all of my chimes. thanks

Pros:

Cons:

Absolute junk. Created DTC's

Herb from Fort Wayne, IN on 5/27/2012

2007 Pontiac Grand Prix
Crutchfield Customer Review (What's this?)

Would pick zero stars if option. Installed and had no problems for about a week. After that my ABS, BRAKE, traction control and stability control lights kept coming on and going off, multiple times while I was driving. thought it may have been my install error. Double checked everything and it's all good. Removed and put factory back in, cleared all codes and haven't had a prob with the lights since. Trying to bypass the pack and get everything to work and have steering wheel control. Definitely not going to buy from that company again. Will continue to buy receivers from Crutchfield, but probably not much else. Very unsatisfied.

Pros: Never had one for more that a week.

Cons: Set codes and has noise through the speakers.

Installed in my 05 Chevy Tahoe

BrossHawg from Ephrata, WA on 5/22/2012

2005 Chevrolet Tahoe
Crutchfield Customer Review (What's this?)

This unit works well and does what it is supposed to. I would have given it 5 stars if it were not for an issue I had after installing. The blue potentiometer does more than just turn down the door chimes (which were very loud at the factory setting). If you turn down the door chimes with the stereo on, it also turns down the gain for the deck. I had the system sounding really good and the wife complained of the door chimes being too loud. In a hurry, I adjusted them down and reinstalled the deck and cleaned up (had to leave for a dinner date). After that, the sound was horrible, and I was pulling my hair out thinking I messed something up. After talking to a tech at Crutchfield, we figured out what happened. You have to turn the stereo off for 10 seconds and THEN adjust for the door chimes. Other than that, all is good.

Pros: *Ease of installation *Functions as advertised

Cons: *Directions could be more detailed (see above)

Worked Great! For Pontiac Grand Prix

Benja from Illinois on 5/4/2012

2005 Pontiac Grand Prix
Crutchfield Customer Review (What's this?)

Worked great with a JVC kw-R500 receiver and the Axxess ASWC steering controls in my 05 Grand Prix GTP with monsoon.

Pros: Worked Great! The warning chimes and Onstar all worked properly and sounded like they were supposed to.

Cons: The directions need to be written better.( until then you can call crutchfield.)

It does what its supposed to

Michael from Ohio on 4/13/2012

2006 GMC Envoy
Crutchfield Customer Review (What's this?)

I got this adapter for my 2006 Envoy Denali with Bose sound. It does what it says its supposed to integrating door chimes and onstar. I don't use onstar so that was not a big deal. I like being able to adjust the door chime level because even on the normal level with the factory radio they were loud and annoying. The Bose sound quality is not quite as clear as it was on my 2000 GMC Jimmy. Not sure if its because of the adapter or just the speakers. One major thing the instructions dont bother telling you is that when the chimes are not playing the adjustment acts as a gain control. This fixed a lot of my sound issues i was having at first with the distortion as many have stated in their reviews. Still not the Bose clarity i had in my old GMC so I may replace my speakers but doing so will not allow door chimes or onstar if you dont go through the factory amp. Hope this helped a few people. Overall it was easy to set up and Crutchfield is always great with service thats why i keep coming back.

Pros: Easy Set up and adjustments.

Cons: Needs a little more detail in instructions but if you have a little knowledge in car systems you should have no problem

GM wiring harness

Clint from Leland, NC on 3/21/2012

This is one time you don't get what you pay for. Should have bought the wiring kit from a different retailer for $30 less that comes with the needed antenna adapter. Plus I got tricked into thinking the steering wheel adapter came with it since it shows the harness in the pic. Why would you include that section of harness (that comes with the ASWC unit) if not included??

Pros: What actually did come in kit worked great. Chimes do sound different but I like the new sound better..seem deeper. Like the ability to adjust sound level of OnStar and chimes.

Cons: Over priced and does not include antenna adapter. Instructions are useless since it doesn't tell you what ALL the wires are for, hope you have some install experience. Tells you to connect the red wire of one harness (that actually has two which need to be connected together) to the red wire of after market radio harness. Also says to connect orange and white which is no problem but doesn't tell you that the same color of wire on the other connector of harness ALSO needs to be connected.

Product worked Crutchfield support worked even BETTER!!

SeanS from Trail BC Canada on 3/6/2012

Seen the previous negative reviews but things worked out perfectly for me. There have been faulty GMOS04 units but Crutch will always exchange a bad one to make you a happy customer. Installed it with a double DIN GPS deck in my 02 grand Am. Monsoon system no onstar. It retained my factory chimes, factory amp, and all functions. I did hit a snag though. After wiring it up it sounded awesome. However, I was only getting audio when the door was open?? The second I closed the door the audio would go mute yet the deck was still running. Open the door and the audio would come back? WTF?? Called tech fearing the worst. No offense but usually tech numbers are dudes reading trouble shooting tips off scripts. It was clear right away that tech knew what they were talking about. Anyways....solution from tech... I hooked the remote wire from the deck to the remote amp on the module, like you would a normal aftermarket amp and it works. Weird considering that remote wire is designed to power an aftermarket amp that I don't even have?? However it solved my problem and now audio works as it should opened or closed doors. In this day and age its extremely rare to be "taken care of after purchase" Crutch's techs came through and assured me if all else failed they would have replaced the item no questions asked. They went the extra mile while on the phone and me in my car troubleshooting.Great product?? That's not why I will be a returning customer. The service is why.Thanks

Pros: worked for my 02 Grand Am as described

Cons: Would agree with most reviews.......the instruction manual for is terrible!! Tough to follow

2003 Yukon with Bose

Dave from Woodbury, MN on 2/24/2012

I was a little nervous about buying this due to the number of negative reviews, so I thought I would share a positive experience. I installed this last night into a 2003 GMC Yukon with the premium Bose and Onstar; however, I do not use Onstar. Everything worked perfectly at the first test. I had no issues with buzzing, distortion, dead battery, crappy sounding chime, not shutting off when I open the door, etc. While the step-by-step instructions were easy to follow, I agree with the others that said it would be nice to have a wiring diagram included. Also, there were no instructions for adding the ASWC. The ASWC part wasn't that difficult to figure out, but it would be nice to have some sort of validation prior to plugging it in. In my opinion, this product deserves 4 1/2 stars, since I believe the functionality far outweighs the mediocre instructions. However, since there are no half-star increments, I am giving it 5, because I am very pleased with how this works.

Pros: Works great!

Cons: No wiring diagram or ASWC integration instructions.

So far so good

Lawrence from Long Island NY on 2/22/2012

2007 Chevrolet TrailBlazer
Crutchfield Customer Review (What's this?)

I needed this unit to install a new Pioneer AVH-P2400BT in my 07 TrailBlazer SS . It is working fine so far , my only complaint is that the instructions aren't very good. They don't even explain what every wire on the unit is for. The folks who write these manuals should really learn how to explain all aspects of their product in a simple manner.

Pros: You need it to retain your door chimes and Onstar

Cons: You need it to retain your door chimes & Onstar. Instructions stink.

Pretty Easy

CSP from Inver Grove Heights, MN on 2/8/2012

Way easier than I thought. This was my first install ever. Worked great with my 2006 Chevy Crew Cab with Bose and Onstar. Instructions were somewhat clear but I easily figured it out. All harness fit to perfection and it did exactly what is was supposed to do. Had to call and ask a few questions but that was expected.

Pros: Everything works Retained Onstar and factory door chimes Worked with current Bose 7 speaker setup Has adapter for steering wheel control built in (unit sold separately)

Cons: Door chime sounds a bit different A little intimidating at first

Adapter kit

Joseph from Texas on 2/6/2012

2006 GMC Sierra 2500/3500
Crutchfield Customer Review (What's this?)

Product works. Little slow on the reaction to the chime. That may be in part to the Bose amp.

Pros: Plug and play.

Cons: Size. Excessive housing make it difficult to place in the confines of the dashboard.

Doesn't Work as Advertised for the Corvette

Mike from Texas on 1/27/2012

2006 Chevrolet Corvette
Crutchfield Customer Review (What's this?)

I installed this to go with my Kenwood DDX 418 and it worked fine when using On Star but it failed in retaining the factory chimes. I ended up with a loud constant whine that was nothing like the factory tones. I took it off and installed the PERIPHERAL module in lieu of the GMOS-04 which resulted in the factory chimes and the On Star interface that I was looking for. I did my research in the audio section of various car forums and those who recommend the PERIPHERAL unit stated that it has the Delphi chipset and GM uses Delphi for their electronics so there is no issue with losing your factory tones or use of On Star. I would recommend researching on various electronics forums and read the testimonies of others who have tested the product instead of read the staff and consumer reviews on this website. Nothing against staff or the fellow customers who have bought this product as I have benefited from such reviews. I'm sure they have done their due diligence but if you are going to invest a lot of time and money to install an aftermarket audio system, you owe it to yourself to do the research so you can make an informed decision. Even after reading this, please look at other sources to do your research so you know you are going into the installation venture eyes wide open.

Pros: There are none. Perhaps reading this review and going with the PERIPHERAL unit will be the positive.

Cons: For the Corvette you lose your factory warning sounds.

GM BOSE Factory System Integration Harness

Owen from Texas on 1/20/2012

2005 Chevrolet Tahoe
Crutchfield Customer Review (What's this?)

The product arrived in brand new condition. The product included detailed instructions of installation. It also had technical support via phone.

Pros: Very simple to install and it works really well. It does everything it claimed to do.

Cons: It is quite large, had trouble getting all of it in the dash board space behind the radio. It doesn't work with the steering wheel volume control. That's a big down side loosing the capability to control the volume from the steering wheel.

Piece of junk

Matt from Frisco, TX on 12/26/2011

Crutchfield Customer Review (What's this?)

Installed along with JVC KW-XR610 unit in '04 Tahoe. Tested everything - worked great. However, within an hour of installation, car battery was completely dead. Stranded my wife out on the road. Started reading the reviews on this thing...sure enough, others having the same issue. Asked Crutchfield tech support guy about PAC brand and said the GMOS is actually what they've had the most success with. (Doesn't exactly inspire confidence). They are sending me another one to try. If this one doesn't work I'm sending it and the JVC unit back. Keeping my fingers crossed.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Bernard from Chicago on 10/6/2011

2004 Chevrolet Tahoe
Crutchfield Customer Review (What's this?)

The trickiest part of the system install but the support team was extremely helpful. After 30mn on this particular product, everything was up and running. Thank-you

Pros:

Cons:

Simple Connection, Inexpensive

kinukawa from Petersburg, VA on 9/23/2011

2005 GMC Sierra 1500
Crutchfield Customer Review (What's this?)

The Axxess GMOS04 adapter and Steering Wheel control adapter (PAC-SWI- JACK) were required for application on my 2005 GMC Sierra w/ Bose and were relatively simple to hook-up. Slightly different sound from original warning bell - smoother tone. I did not have to adjust volume for Onstar or bells and I was using 4V pre-outs... not sure why people are having issues w/ that? Miscellaneous steering wheel-control wires (red/black mic-type jack) and Onstar harness that aren't covered in the instructions are unnecessary in 2005 GMC Sierra using PAC's SWI-JACK. Took about 4 hours and I was taking my time with everything. Quoted over $600 for same work from an independent stereo shop because it was "tricky work"...over 50% savings and no headache.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

ChvyBoy from Columbus,Ohio on 9/17/2011

Crutchfield Customer Review (What's this?)

First off fast shipping, ordered it on Wednesday afternoon got it Friday. At first it seem complicated. But after reading the instructions it was as easy if not easier than hooking up a regular harness cause you don't have all the wires to match up. The door chime does sound different. But I don't mind it and I like the fact that you can change the volume of the chime. I have a Trailblazer with Bose system and I installed a Pioneer Double Din. I don't know if it was cause of the harness and the way its hook up or what but my speakers sound way better now than it did with factory deck. 5 stars all the way and worth the price. Don't let someone cheat you out of having you door chimes, onstar and amp.

Pros:

Cons:

confusing

pj from Richmond, VA on 8/15/2011

Crutchfield Customer Review (What's this?)

Very confusing installation manual. There are specific instructions for the Corvette and the wire colors and labels made it even more confusing. Just expect to be on the phone with the techs on this part of the installation. Otherwise, everything works.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Howie from apple grove WV on 8/10/2011

Crutchfield Customer Review (What's this?)

simple instructions easy hookup after the adjustments brings out a good sound and keeps the factory accessories working like they should

Pros:

Cons:

Don't install without this

Tim D from Woodbury, MN on 8/2/2011

Crutchfield Customer Review (What's this?)

Made the install straightforward and worked perfectly. OnStar, Bose and Chimes all worked great without any adjustment. Only complaint is my 4 volt pre-out deck clips the interface, but I am installing a Boston Acoustics outboard amp so that will no longer be an issue. Thanks Crutchfield!

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Angel B. from California on 6/11/2011

2000 Chevrolet Impala
Crutchfield Customer Review (What's this?)

I installed it in my 2000 Impala and it was terrible I had to bypass the RCA hookup and the door chimes are barely noticeable. I don't recommend it, its not worth the price. I gave it one star but it really needs no stars.

Pros:

Cons:

Great product and support, terrible instructions

JimK from Southern Maryland on 5/15/2011

2004 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

This product works as advertised to integrate an aftermarket receiver into a GM premium or Bose system. The instructions are not very good. No diagram and there were undocumented connections for the steering wheel control unit. Crutchfield cost on this was only half-price with the receiver order. Not sure if that was a special or standard offer. IMPORTANT NOTE: You will also need a Metra Access ASWC in addition to this control unit to activate the steering wheel controls. So you need both units to get full functionality. Crutchfield tech support was helpful here but it should have been more obvious when I placed the order.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

JohnQ from Chicago on 5/14/2011

2003 Chevrolet Tahoe
Crutchfield Customer Review (What's this?)

It's expensive but you won't be able to do the job quickly without it. Installed in a 03 Tahoe with Bose with no problems. It retains the car chime over the speakers and lets you use your Bose speakers normally. Sound quality is really good.

Pros:

Cons:

It worked for me.

Keith L. from Utah on 5/12/2011

Personally, once I found out what the blue antenna signal wire was for, I felt the whole system works flawlessly (or almost). Many people from other reviews I have read complain about how the door chimes sound and that they sound like a toy. Well, I feel the chimes sound almost exact to my original door chimes that were factory installed. The only problem I have with that is...while there is no engine interferance with the sound coming from the newly installed stereo, there is noticeable interferance while the chimes play. Currently, I am not sure what I can put in place to filter out the engine noise for the chimes only so they sound crisp and clean and not affect the sound of the stereo. My only other frustration with the unit is, as other reviewers mentioned, the chimes are extremely loud. I had to turn the small volume control down to almost off in order to get the loudness to a level I was comfortable with. It does maitain the power to the my new unit after the key has been turned off. I don't think it holds it as long as the original 20 minutes that the car was installed with. But then, I don't ever sit in my car longer than that with the key turned off. Basically the unit performed as described. Wires were marked well. It was pretty self explanitory.

Pros:

Cons:

No chimes, well almost

Marshall from NC on 5/3/2011

2003 Pontiac Grand Am
Crutchfield Customer Review (What's this?)

The chimes seem to be the same tone, or close enough if they aren't. The problem is they are so soft that you won't hear them with the radio on. I contacted Crutchfield support who said there was nothing they could do. The radio works so they consider the product to be fine. I contacted Metra and they seem confused as to whether or not I turned the volume all the way up or not (I did of course). That's why I gave it two stars. The chimes are THAT important in case of problems. Otherwise the box is perfect if you read the instructions, have the right adapter, and check your wiring. Hooking it up to a Monsoon or similar amped system is quite easy. Sit down at your kitchen table and wire the adapter to the radio first. Then when you get to the car you just plug it all in and enjoy the music.

Pros:

Cons:

Disappointment

andy from indianapolis, IN on 4/26/2011

I bought this with a new pioneer head unit for my 01 grand am w/ monsoon sound system. i installed it and the sound was very quiet and distorted. There wasn't an even balance of sound. the front driver side speaker could barely be heard and the rear speakers were way louder. after five minutes of listening to the radio it completely shut off. I checked all connections and it wouldn't work, so i rewired everything and it wont even turn on now.

Pros:

Cons:

didnt work but Crutchfiels made it right

Anonymous from Greenville SC on 4/21/2011

2004 Chevrolet Tahoe
Crutchfield Customer Review (What's this?)

Wired up the product and the chimes didnt work. Front speakers didnt work. Spoke with Tech and did some tests and they immediatly sent out new product. Plugged it in and all worked perfectly. 2nd one worked great

Pros:

Cons:

Metra GMOS-04 Wiring Interface

andym from indianapolis, IN on 4/20/2011

2001 Pontiac Grand Am
Crutchfield Customer Review (What's this?)

slightly hard to hook up if its your first car radio install.

Pros:

Cons:

Thank Goodness

RogerF from Midwest USA on 3/28/2011

2002 Chevrolet Impala
Crutchfield Customer Review (What's this?)

If you have GM's class II databus, then you may know it can be complicated to integrate a new radio to your vehicle. This device makes that integration a plug and play process. If you are handy with hand tools and comfortable with wiring then this will make your installation a breeze!

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Jeff from Forest Hill, MD on 3/24/2011

Crutchfield Customer Review (What's this?)

If you have a GM this is a must. Clear install instructions, works great.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

WayneN from Minneapolis, MN on 3/14/2011

2003 Chevrolet Monte Carlo
Crutchfield Customer Review (What's this?)

This adapter worked as it stated to support the amplified bose factory system and chimes in my 2003 Monte Carlo. After adjusting the audio screws on the circuit board for sound output, I was able to get the sound to my liking. It all worked great and was easy to install. Other brands of harnesses I looked at required multiple harnesses to support all the features of this one and were much more expensive.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Anonymous from Corinth, ME on 3/8/2011

Crutchfield Customer Review (What's this?)

makes for an easy hookup, but the door chime is almost inaudible

Pros:

Cons:

Does What its supposed to do

KJr from Galesburg,IL on 2/24/2011

Crutchfield Customer Review (What's this?)

It worked like it was supposed to. The only problem I had was forgot to hook up one wire and a call to customer support, cleared that up for me. Would buy again.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

dc from Huntsville,AL on 2/17/2011

2003 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

This adapter works well if it arrives functional. The 1st one sent with my order had a bad channel on it. After doing some research on the internet, it seems that there is an unacceptable probability that you'll get a defective unit. Crutchfield was great with the return and sent a new one out immediately... so +1 for their customer service. The 2nd unit worked out of the box and so far so good.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

buckfever5 from Illinois on 2/13/2011

2003 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

Quick and easy install in my 2003 Silverado. I spliced the deck harness to the GMOS in the house before I pulled the factory head unit out. Once I pulled the factory head unit it was smooth sailing. I was a bit concerned about where the GMOS unit was going to go in the dash, but there's plenty of room behind the head unit to tuck it out of the way. Everything works as it should. The door chimes have a different tone, but it doesn't bother me.

Pros:

Cons:

Ok but a little dissapointed

LP from Green Bay, WI on 2/12/2011

2005 GMC Yukon XL
Crutchfield Customer Review (What's this?)

Ok just to be straight, this actually works just the way it is supposed to and the instructions were easy to follow even for a first time installer. What I'm dissapointed about is that I lost the audio for my factor installed DVD Entertainment system in the back. Crutchfield had a disclaimer before I bought this saying that I would so it's not their fault. What I'm dissapointed about was that right after I bought and installed it I found out from one of Crutchfield's suppliers that the new GMOS-14 which would have given me this option was only weeks away from shipping to them. Even though it's not available on line it is in the test phase and it would have been nice to know that it was out there. Now I have to go through the trouble of pulling everything apart when it does become avaialable on-line. The nice thing was that Crutchfield told me that if/when it becomes availalbe on line to call back and they'll work something out, either as a one for one trade in or just paying the difference if the new one is more expensive. So Kudo's to Crutchfield for that. You guys are ok in my book, just give me a little heads up next time.

Pros:

Cons:

Did not work

Paul from Illinois on 2/7/2011

Crutchfield Customer Review (What's this?)

Installed and had crackling in speakers. It took a while to trouble shoot what was causing this, ended up replacing with a PAC OS2 harness and now works fine. Crutchfield did refund my $ on this return. Thank you Crutchfield.

Pros:

Cons:

Not sure on this item yet

Mike C. from New Orleans, LA on 2/4/2011

I purchased this device to tie my Clarion into my '06 Tahoe. Wiring was straight forward and relatively easy to lay out on my workbench with both sets of instructions (this device and the radio). My problem with it is that there is a variable resistor that controls the output to the radio and increased/decreased your volume output. Initially I would crank the radio up all the way and not get the volume I used to get, and no, I was not playing it at a deafening level. I have found, maybe it's the radio but I doubt it, that my sound level is simply not as robust now as it was once and since I'm feeding out to the Tahoe's OEM Bose system, I would think I would get the same, if not better sound and volume, but I do not. What the cause is yet, I'm not totally sure.

Pros:

Cons:

Need to go back to the drawing board GM

bkenner from SC on 1/31/2011

Crutchfield Customer Review (What's this?)

This product is completely unsatisfactory. Causes severe distortion. In my 04 Yukon application, tech support couldn't determine fix. Don't waste your time or money. Problem lies with complex GMC system. I gave up and returned entire GMOS and head unit package and stuck with stock GM radio - bummer.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

BartK from Houston, TX on 1/27/2011

2003 Chevrolet Tahoe
Crutchfield Customer Review (What's this?)

Easy to install. 2 orange wires on 1 harness through me of though, instructions didn't specify to connect both from that harness to 1 orange wire on the other harness, but a quick call to Crutchfield support solved that.

Pros:

Cons:

Worked like a charm - 2006 Chevrolet Trailblazer LS

SullyCuse from Sugar Hill, GA on 1/4/2011

Worked like a charm. Used this with a new Clarion CX400 Head Unit in my 2006 Chevrolet Trailblazer. I do not use ONSTAR, so not sure if that works or not, but all the chimes work, as well as the delay shut off of the unit until the door is opened after turning off the ignition! So with everything else working, I am assuming the ONSTAR is still functional. Directions were concise and very easy to follow. Hooked all the wires up to the head unit wire harness in about 20 minutes. Then just a matter of plugging into the existing harness in the vehicle! Sound is fantastic and retains the BOSE amplifiers located on the speakers. 100% recommend this for any vehicle with existing ONSTAR and BOSE speaker set up!

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Anonymous from austin, tx on 12/2/2010

Crutchfield Customer Review (What's this?)

great product. heard all kind of reviews on it and was a little worried about the install. they were all wrong. took no time to install & worked like advertised. soud was great & did not even have to adjust output level or door chime volume. installed it in a 2003 chevy suburban. used a pioneer avh-p3200dvd.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

BMH from Illinois on 11/29/2010

Crutchfield Customer Review (What's this?)

Installed this unit in my 2004 Silverado with Bose Speakers and Pioneer FH-8000BT. Unit works good with Onstar. It sounds like chime noise comes through the speakers now which sounds a little different but there is an adjustment to turn it up or down. I turned mine down enough that I can hardly hear it and it's not an issue. Instructions were good and easy to wire up.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

JD from OK on 11/10/2010

Crutchfield Customer Review (What's this?)

Quick and Easy - Very Simple Hookup - Smaller and Less Chance for Confusion than Other Units I have Used to Fix the Issues resulting in Putting What You Really Want for Sound in a New Ride! I am a Huge Fan of Clean Wire and Installs - and was Happy that this unit tucked back into the Dash so Cleanly! Thank You for Offering a Quality Product!

Pros:

Cons:

Almost perfect

Cliff from Florida on 10/11/2010

2007 Hummer H3
Crutchfield Customer Review (What's this?)

I have to admit, I was a bit concerned when I saw the negative reviews on this. But Crutchfield recommended it and I've never had them steer me wrong. I used it to install a new Pioneer head unit into a 2007 Hummer H3x. It made what would have been a nightmarish install into a piece of cake. The instructions were fairly clear, although an explanation of what each wire is supposed to accomplish rather than just "illumination" wire would have helped on some confusions, e.g. "connect this to the wire your stereo uses for constant power even when the car is turned off." I don't know why some have such terrible sound, mine is glorious. And being able to retain all the OnStar and other sound functions as well as easily tapping into the Monsoon amps/speakers easily make this a no-brainer. Especially getting it for half-price since I bought the new head unit from CF.

Pros:

Cons:

Only supports up to 3 volt pre am output

Cliff from Burke, VA on 10/2/2010

I used the GMOS-04 to install a Kenwood DNX960. The GMOS-04 states in the manual that it only handles up to 3 volt pre amp outputs. The Kenwood DNX6960 has 5 volt outputs. I was worried abou this after reading the review here and sure enough the head-unit sounded terrible. I talked to tech supprt at Metra and they said it was being over driven by the high voltage outputs on the Kenwood. They suggested I get a line level converter and convert the speaker outputs on the Kenwood to pre amp and they would be 2 volt and would play well with the GMOS-04. It worked like a charm and what a difference. Now the Kenwood sounds like I thought it would. Best of all the vehicle retains all of the factory operations (door chime, delay power off, Onstar, etc.) If you are using the GMOS-04 with pre amp output over 3 volts you should consider this option.

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Cons:

My review

Jim from Severna Park, MD on 9/28/2010

2003 Chevrolet Suburban
Crutchfield Customer Review (What's this?)

Excellent product and excellent website. The website let me know that I needed the adapter before I installed my aftermarket receiver. Once I got the adapter, everything fit and worked perfectly. The product provides functionality for the factory set-ups and allows me to add additional hardware to the system. I really appreciate that Crutchfield had the cohones to provide installation instructions. So many wimp out and say hire someone - I guess its because, unlike Crutchfield, they don't lead the customer to and provide appropriate products to complete the install.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Anonymous from Cincinnati Ohio on 8/27/2010

Crutchfield Customer Review (What's this?)

I would have given a 5 star rate if the instructions were correct. it states to adjust the chime and audio pots the wrong direction and to disconnect the unit before doing the adjustments. When I called for advice on the second time I was told to leave it connected and turn the pots the oppsite direction as stated and it work great!!!!

Pros:

Cons:

Doesnt Work

Anonymous from NY on 8/13/2010

2002 Chevrolet Impala
Crutchfield Customer Review (What's this?)

Well after trying two of these in my 02 Chevy Impala, these will not work. All you get is Very Low Sound. Even when adjusting the knobs on the side to adjust the volume they will do not work. So beware if you plan on installing this into an 02 Impala. There was also nothing fancy with this car as it didnt have either Onstar or a Bose system.

Pros:

Cons:

GMOS and Limitations

cameron from Boston MA. on 6/10/2010

Crutchfield Customer Review (What's this?)

Yes this adapter allows you to retain some of the functions of your Escalade (door chimes, onstar interupt etc) but don't be fooled into thinking it will allow for a seamless interchange, As it does not allow you to use the "on steering wheel" controls, the factory cd changer, factory navigation antenna, factory xm antenna, nor the factory xm receiver. Just so you know prior to installation. Tip- this is not addressed in the g-mos instructions, but worked great for me: run a bullet type male plug on a wire, from the red female receiver on the "car" side of the g-mos (shown in the photo) to a momentary switch (any type, mounted anywhere even under the dash) and from said switch to a ground. this allows for modification of onstar and chime volume without removing dash unit again.

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Cons:

Does Good Job - Easy to Install

Anonymous from Altamonte Springs, FL on 4/29/2010

2004 Pontiac Grand Prix
Crutchfield Customer Review (What's this?)

This unit does the job. It was easy to install and makes installing an aftermarket radio that much easier too (less messing with the factory harness). It changes your door chime tone. But I like it and a friend said it reminded him of the monorail at Disney (the chime you hear before the voice comes on to say 'stand clear of the doors ; the monorail is about to depart...) Couple issues I had were minor (somewhat). 1. Its kind of bulky so I had to position it precisely behind the panel of my Grand Prix '04. 2. The instructions I received needed updating. They mention turning the dials/screws counter-clockwise for increased tone and amp volume. It's the opposite. I think the reason for this is because it looks like one had to open it up to change the volume by using a screwdriver. Now the makers have enclosed the unit. So when you turn the screws (on the outside) clockwise, through some mechanical wizardy you are turning the inside screw counter-clockwise. The documentation hasn't been updated.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Luke from Murfreesboro, TN on 2/18/2010

2003 Chevrolet Suburban
Crutchfield Customer Review (What's this?)

Extremely easy to install. I looked at all the reviews before purchasing and saw some said it was confusing but thought I would give it a shot. It was one of the easiest things to wire to a new reciever harness, all you have to do is match up the colors. But one thing make sure you test out the door chimes before you mount your stereo. I did not do that and when I started the stereo with the door open the chime was so loud my wife heard it inside the house. I had to take out the stereo and turn it down.

Pros:

Cons:

Works GREAT

Anonymous from Corpus Christi Texas on 1/18/2010

Crutchfield Customer Review (What's this?)

I bought this to replace the Bose factory head unit in a used Z71 Tahoe I recently had purchased. I will admit that after reading some of the more negative reviews it was with some trepidation that I selected it, but with Crutchfields reputation for "making things right" I figured that if it just flat did not work right I could always send it back. Got it in, yanked the dash and old unit, wired this into my Sony CDX-GT7110 and turned the key. I never should have been concerned, it worked even better than I would have thought. Just a couple of minor adjustments to raise the gain and lower the chime volume (LOUD in the as-shipped setting) and it was ready to go. Total of just over an hour from start to finish and the sound is fantastic for what is still a partial factory set-up of amps and speakers. I had been planning to replace the speakers eventually, nope, no need for that now. Unit is well worth the price.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Soviet from Blaine, MN on 1/14/2010

2002 Chevrolet Impala
Crutchfield Customer Review (What's this?)

I drive a 2002 Impala, and installed this adapter. However, I didn't just replace my HU, I replaced my HU, speakers, added amps and a sub. The instructions were a bit confusing at first, but looking at it a second time it all became clear. Since I did not just replace the HU, I had to run the left wire from the adapter to a speaker (just a small one from radioshack) that is just screwed into the bottom side of the console in order to retain the warming chimes for door ajar, change oil, etc. My only problem with this adapter was its size, but I was able to shove it back and down to the right.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Sean from Arkansas on 1/8/2010

2003 Chevrolet Tahoe
Crutchfield Customer Review (What's this?)

I had been debating over changing out my factory radio for years, because of the horrible reviews of this harness. I finally gave it a try. The installation was tedious, and I had some initial problems with getting everything working properly. But, I finally got it working, and it works great! Thanks to the Crutchfield techs on the phone line, we worked through the problems and got it going. I was able to change the radio, keep the Bose speakers, and retain chimes. Make sure your radio has 2-3 sets of pre-amp outputs b/c 2 sets will be devoted to this harness (use the 3rd for adding another amp for subs). Stop hesitating and give it a try!

Pros:

Cons:

NOT WORTH THE MONEY

rmyoung123 from Iowa on 9/3/2009

2001 Chevrolet Impala
Crutchfield Customer Review (What's this?)

Dont waste your money on this product, did not work properly from the start, tried resetting it per a Crutchfield tech advisor, still did not work. Sound was horrible, hardly any volume, had to turn line input all the way up, which distorted sound even more. The OnStar had to be turned all the way up to just be barely heard. Only good thing was I was able to cut the wiring harness off and wire radio directly. Then added any external powered speaker for the door and key chime, and OnStar. Crutchfield needs to find a better company for this type of item.

Pros:

Cons:

Nice

Rat88 from Youngtown, Oh on 8/26/2009

Crutchfield Customer Review (What's this?)

Very straight foward directions. Just hook up all the wires and you are done. It works just like it is supposed to. Just a little bit of adjustment had to be done on both the chime level and the audio level......that is all different depending on who you are. There is only one thing that I could say......the box itself is a little bulky so you gotta have some space to tuck that thing in somewhere.

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Cons:

Purchace a Scosche instead

Joshua from Minneapolis, MN on 8/21/2009

I purchased this unit to pair with a Pioneer FH-P8000BT in my 2004 chevy suburban. This unit also connects to a Rockford t-600 AMP powering 2 X 12 inch Rockford Punch subs (Had to add a 2F capacitor as well). I originally didn't replace the factory stereo and the system sounded pretty good. I wanted the upgraded pioneer as I was able to use adjustable sub outputs and 7 band eq on it. Before adding the GSOM I had zero alternator hum. After adding the Metras GSOM I suffered from terrible alternator hum. I was then forced to purchase a Scosche adapter what solved all my issues. Other than the alternator hum the Metras GSOM worked great for everything else however if you have high end equipment I would just go with the Scosche to begin with. Teaches me for not spending the $50 extra.

Pros:

Cons:

Not worth the money...

Ron from Walnut Creek, CA on 8/18/2009

2003 Chevrolet Avalanche
Crutchfield Customer Review (What's this?)

Interesting little blackbox that is suppose to keep a lot of your functionality when replacing your standard car stereo (Chevy Avalanche). Installation wasn't really as straight forward as I thought. Took some time to follow the directions to get it setup. Once connected, my new 80watt JVC HD Radio sounded like cheap headphones. With the volume on maximum, I could only get about 1/2 the sound as from my old radio. The door chime doesn't work, however, turning off the car and the stereo remaining on till the door is open does (standard feature on the Avalanche). After hours of double checking everything I finally resorted to bypassing the blackbox for the speaker wires and going direct to the original car connections. Bingo, the stereo works great, tons of volume. So the only thing that seems to work as part of the blackbox now is the stereo remaining on after the key is off till the door is open. This feature alone is not worth the cost of the device. I'd save the money and get a direct wire harness for the JVC and forget this device.

Pros:

Cons:

Good Product

joe from Los Angeles, CA on 7/30/2009

Crutchfield Customer Review (What's this?)

To be honest, I was a little skeptical about this product from the reviews I read, but after following all of the installation instuctions for item it worked very well on my 2006 Trailblazer SS! After adjusting the levels, the onstar and chimes functioned and sounded like the OEM ones. It appears that the interface works well with newer vehicles, but does not with older ones. Maybe the codec on the serial bus is not compatible with older vehicles. I hope this info. helps those of you who are concidering this product. 2006 Trailblazer SS, factory Bose speakers and amp and Kenwood DNX5120 DVD Navigation Receiver.

Pros:

Cons:

At least the connections fit the stock harness

Larry from MD on 7/6/2009

Crutchfield Customer Review (What's this?)

The distortion, lack of volume, and overall bad sound when connecting the head unit to the RCA cables coming out of the box is true. The quality of the box itself, is not worth 20 dollars, let alone this much. The adjustments for the chime and audio input volume bend with little pressure and seem to vary in sound depending on if there is pressure from the screwdriver adjusting them, no pressure from screwdriver but adjusting carefully by hand, and then when they are just not being adjusted at all they are a different volume. Overall I would buy a different harness, I made do with this one by bypassing the box and tapping into the harness on the other side with the speaker wire outputs on the back of my head unit and it sounds perfect now. Basically all I needed out of this kit was the grey connector to stock harness with wires sticking out the back, the black box is just a big waste of plastic, space, and your time. Also don't connect the mute wire on the harness to the mute wire on the back of your head unit, just don't do it, unless randomly when your driving do you want your head unit to mute then unmute. Really need to change the rating system so you can give zero stars.

Pros:

Cons:

Works as described

Mike from Lebanon, IN on 7/4/2009

2003 Chevrolet TrailBlazer
Crutchfield Customer Review (What's this?)

This product works like it is supposed to. At first, the sound coming from the speakers sounded awful, but once I found out that I could turn up the unit (much like turning up the gain on an amp) it sounded a lot better. So much better than the factory stereo. This was put into a 2003 Chevy TrailBlazer with the Bose stereo unit as factory. I replaced the factory head unit with a Kenwood DDX514. I was concerned about the low end (bass sounds) before the install, but this put my mind at ease. I do hear a slight alternator whine at times that was not present with the factory stereo, but I am not sure if it is from this unit. Usually, alternator whine is from bad grounding, so I think I will try to add another ground wire to see if that helps.

Pros:

Cons:

First one defective.

Roger from Austin TX on 5/14/2009

Crutchfield Customer Review (What's this?)

The first one I received was defective. Did not respond at all. Called crutchfield and they sent a new one out. Crutchfield took good care of me. I hate having to shell out the money for this thing but wanted the functionality of my onstar. I read all the reviews and was leary about ordering but knew crutchfield would make it right so I ordered it. This second one works as described and havent had any issues as of yet about a month. It is in my 2006 Chevy Silverado Crew Cab. I really dont know why the company that makes these does not do better quality control.

Pros:

Cons:

Does what it's supposed to do

Slick from Sims, NC on 5/11/2009

Crutchfield Customer Review (What's this?)

This was easy to hook up in my 04 GMC Sierra with onstar/bose system powered by an Alpine CDA-9886. It does change the sound of the chime but nothing to make me want to take it out. Only problem I would have is the radio doesn't seem to be as loud as expected even on 20-25 volume(which my wife says is to loud for her at 10)but maybe that's just me.

Pros:

Cons:

Avoid at ALL COSTS

Matthew from Marquette, MI on 4/24/2009

Crutchfield Customer Review (What's this?)

This is an excellent product if... You DO NOT want your stereo to work. I recently replaced the head unit in my 2002 Impala with JVC Arsenal KDA605 and I was forced to use the Metra VT-GMOS-04, as it is the only option Crutchfield gives. I tried one, and it didn't work. I had to get another billed and shipped to me, and this one also did not work. I am so upset with the Metra units. After Metra installation: * My stereo's sound quality sounded like a pair of dollar store headphones (I use stock fronts, Infinity Reference 6x9" 3 way rears which are hooked up to the factory amplifier). * The sound quality varied, while always sounding extremely muted (with volume half up, you could not hear it, and at max volume it sounded distorted and very quiet). It would go slightly louder at times, and then randomly go back to being extremely quiet. * The door chimes did not work correctly * The Metra units distorted bass frequencies and disrupted fade * Loss of time and money DO NOT BUY THIS UNIT and instead do some research on other brands. THEY do exist! I bought another unit and everything now works like a CHARM. OVERALL RATING: -5 stars. This product does not fulfill it's purpose, is not quality, and I would have been better off installing a rock in it's place - at least the rock wouldn't have cost me anything.

Pros:

Cons:

Necessary piece of junk

CDTech from MI on 4/20/2009

Crutchfield Customer Review (What's this?)

As stated in the title, the GMOS-04 is a necessary piece of junk. I installed it in my 2001 Impala inline with a Blaupunkt Hamburg 57. The Blaupunkt is awesome, the GMOS-04 is not. You can here alternator wine coming through the speakers and often times when adjusting balance and fade you here a "scratching" noise coming through the speakers. I have adjusted the unit as per the instructions (you have to take the top off the unti to do this) but the sound it still limited. After spending the ammount of money that I did on my set up, I was not going to settle for the poor sound quality. I bypassed the GMOS-04 by using the built in amp on the receiver and running new lines to the spearkers. I wired in a small speaker under the dash to retain the chimes (the one good thing about the GMOS-04 is that you can retain the chimes). The sound is a lot clear, and the alternator wine is gone. A lot of extra work, but worth the listening pleasure in the end.

Pros:

Cons:

Seamless in my GMC w/Kenwood

Sean from Albany, OR on 3/24/2009

2005 GMC Sierra 1500
Crutchfield Customer Review (What's this?)

This worked seamlessly and perfect in my 2005 GMC Sierra Crew with Kenwood KDC-X493. Can't ask for much better than that.

Pros:

Cons:

Working for me...so far!!!

Yellaboy00 from Ramstein AB, Germany on 3/17/2009

2004 GMC Yukon Denali
Crutchfield Customer Review (What's this?)

I got this interface installed in my '04 Yukon Denali along with the iPod interface and the Kenwood DNX7220 (Not DNX7120 b/c the Military made the 7220 video/region free). I didnt want to lose my Onstar (even though I've never used it but friends recommended it), BOSE amp, and the chimes. When we fired the truck up I did hear the crackling noise in the speakers and decided to pull the unit out and make sure there were no loose connections. I had my installer solder all connections to ensure there weren't going to be more problems and there were none. We turned up the gain and made sure the chimes were fine and went about installing other accessories in the truck. I was sketchy about the GMOS but unfortunately its the only thing out right now, so I took my chances as did everyone else who purchases after market stereo accessories. Thanks for hearing me out and thank you Drew for the accessories I just got and will continue to get from Crutchfield.

Pros:

Cons:

Works

JP from Clarkston, MI on 3/15/2009

2009 Hummer H3
Crutchfield Customer Review (What's this?)

It seems to work pretty good. It has been about a week since I put it in. Just need to make sure you read all the instructions. It's connected to an Avic-N4 in a 09 Hummer H3T with onstar.

Pros:

Cons:

Works Great!

Matthew from Idaho Falls, ID on 3/8/2009

2007 Pontiac Grand Prix
Crutchfield Customer Review (What's this?)

While this product is a bit bulky, it worked flawlessly for me. I have warning and door chimes along with my aftermarket Pioneer deck all in play. The stereo mounting kit for the 2007 Grand Prix is awesome too! I integrated this into my existing monsoon system and it's pretty pimp now (for utilizing stock speakers). Following the included directions, I had everything mounted and working in about 1 hour. The only downside to utilizing this and an aftermarket deck is that you lose the time/timer functionality of the onboard computer. I can live with that as I mostly use the Real Time Fuel use and the Boost option. Only thing I can complain about is UPS's extremely slow shipping... FedEx FTW! I hope everyone starts using FedEx again... They rock.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

steve from Utah on 2/13/2009

Crutchfield Customer Review (What's this?)

Instructions were very good, installed without messing it up the first attempt! it does change the tone of the chimes slightly. My car doesn't have ONstar so I can't comment on that. I wouldn't have attempted the install without this accessory.

Pros:

Cons:

No problems...

Sue from Killeen, TX on 2/8/2009

Crutchfield Customer Review (What's this?)

Was worried about ordering this product after reading reviews, but based on their warranty I ordered anyway. Order arrived earlier than expected. Had this installed locally in an 05 GMC Sierra - no problems at all and everything sounds great.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Steve from Saline, MI on 12/31/2008

Good thing I got this through Crutchfield, because I've had to return this item three times now. The first time I installed it, the radio came on, but there wasn't any sound coming from my speakers. Returned it, got a different one and it worked great for about ten minutes. Now I'm running into the same problem. I talked to the manufacturer and they told me that this issue has been showing up more and more, so they're working on a fix. Until then, they told me to keep returning it until I get one that works. I'm tempted to buy a case of them and try them one by one until I get one that works and just return the rest. That way I don't have to wait a week each time Crutchfield has to send me a new one. I can't believe that Metra is still selling these.

Pros:

Cons:

SO FAR SO GOOD!

Rich from Winlock,Wa. on 12/30/2008

Crutchfield Customer Review (What's this?)

Well I was a little worried about this thing after reading all the bad reviews but I decided to get it. So far so good! I installed it in a 2006 Chevy Silverado w/o OnStar. Wiring is straight forward (Good instructions). Had to adjust door chime volume which is very easy.Stereo sound quality and volume are great! The most difficult thing was finding space for all the wires and the module itself. If I didn't get this at half price I'm not sure I would have got it. ( At full retail it just doesn't seem worth it.)

Pros:

Cons:

works fine

Scott from Pontiac, IL on 12/26/2008

This thing is easy to install, just match up your wire colors and solder them and shrink tube them together. The only problem I ran into was that it is almost too big to fit in the dash with the receiver, but the sound is clear and everything works as it should.

Pros:

Cons:

Worthless

Clay from Houston,TX on 12/24/2008

2005 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

Spent my whole day off trying to make this thing work. First unit wouldn't signal the Bose amplifier and was declared defective. So I got another one. The new one won't power the head unit. If you're forced to use this device, have it professionally installed. They should have enough spares to find one that works. I'd pay any price not to deal with the headache.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Matt from Arizona on 11/18/2008

Crutchfield Customer Review (What's this?)

Installed easily, but had a loud static sound (engine noise) coming though the speakers. I am going to return it for a new one and see what happens. I won't get my hopes up.

Pros:

Cons:

Metra GMOS-04 Wiring Interface

Joseph from Jeffersonville, PA on 11/17/2008

2001 Chevrolet Impala
Crutchfield Customer Review (What's this?)

Useless!!! Does not work!!! Do not buy it!!!

Pros:

Cons:

Metra GMOS-04 Wiring Interface

golden from Central PA on 11/7/2008

2003 Chevrolet Tahoe
Crutchfield Customer Review (What's this?)

I bought this for my '03 Tahoe and Kenwood DNX 8120. Im on my third unit - and why I bothered replacing them this far I have no idea. The first one resulted in severe crackling, engine whining and popping, the second one simply caught on fire, and the third one has brought on the same crackling, engine whining and popping as the first. I went through madness wiring up noise filters left and right only to find out that when I finally bypassed this - everything worked like a dream. The sound was beautiful and there was absolutely zero distortion noise. Even though Ive lost my chimes, with a simple output convertor ive retained all Bose amp functions. How this unit works for others I will never know. It robs your sytem of its true potential and simply does not work. Dont waste your time and money on this.

Pros:

Cons:

Good Product

Thomas from Minneapolis, MN on 11/6/2008

2005 Chevrolet Suburban
Crutchfield Customer Review (What's this?)

I just installed this in my 05 Suburban. No Problems, no adjustments. Worked perfect. Door chimes are perfect level. Radio sounds awesome. I paired this with JVC HDR30 HD Radio. I too was scared by the bad reviews. But it was split right down the middle. Good and bad. So I took a chance and I'm glad I did.

Pros:

Cons:

there is no lower than 1

chris from Pittsburgh, PA on 10/15/2008

2005 Chevrolet Impala

i recieved this product today and installed in my 05 Impala its the biggest waste of money ever !!! speakers pop and crackle, chime turned all the way up and you can hardly hear it tons of distortion no matter where it is adjusted to, i am a GM certified techition i should have went with my gut and just wired it in myself without wasting my money on this!! so i did just that set this on fire did the rain dance and hard wired my eclipse unit works beautifully wired a aux. speaker for the onstar rewired onstar and aux. speaker for chime everything is great dont buy this

Pros:

Cons:

Surprised Crutchfield sells it. Zero stars was not an option!

michael from Granby, CT on 10/8/2008

2003 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

Like most other reviewers, I have been a Crutchfield customer and fan for many, many years, and always happy with their service. That being said, I am surprised by this junk, and more so that Crutchfield continues to sell it after so many bad reviews. I installed it when I replaced the non-amplified Bose system that came in my truck with a Pioneer P7800MP head unit. Cheap construction, all the noise others complain about and the door chime varies from silent to blasting, each time is different ( I do not have Onstar). The remote works maybe 1 time in 50, dimmer does not dim. The only thing that has not happened so far is the smoking-I bought a Scoshe adapter which will install soon and hope it is better. Again, Do not waste your money!! Crutchfield should do better!

Pros:

Cons:

GM Factory Integration Adapter

Franklin II from Washington, DC by way of New Orleans, LA on 9/12/2008

I recently used this product to replace the factory bose disc changer in my 2002 GMC Envoy with the Pioneer DEH-P3000IB. The instructions were fairly simple and I have not had any problems so far. The door chime is a little bit louder now, but that can be adjusted. I did have to adjust the audio volume because I wasn't able to hear my radio at low volume settings. Now that everything is set properly, I think this product will fulfill its duties just fine.

Pros:

Cons:

Does what it's supposed to with no issues

Marc from Boise, ID on 8/25/2008

Crutchfield Customer Review (What's this?)

I was very hesitant to install my new head unit with this adaptor due to the number of negative reviews, however it installed perfectly, did not seem cheap or have poor fitment, works as intended, and doesn't negatively impact the car's battery, electrical system, or sound quality in the least. I feel a little bit ripped off because this sort of thing should be included in the free installation tools which crutchfield provides with the purchase of a head unit, and instead I had to pay this much for it plus $70 for the steering wheel controls, but at least after paying that money it worked perfectly. I did tightly tape the box shut to be on the safe side after reading the other reviews, but I really don't think that was necessary; it fit together very well without the tape. The chime was a good volume, and it retains the player until the doors are opened and everything. Not sure about onstar because I don't use it. For those who want to upgrade all your sound system, this robs your front and rear pre-outs, so you can only add on a subwoofer and have to keep the factory high end. I've heard there is ways around this, but keep it in mind. It's good enough for me though with my Bose speakers and factory amplifier.

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Dead Battery

Troy from Palmdale, CA on 7/20/2008

2003 Chevrolet Silverado 1500
Crutchfield Customer Review (What's this?)

I received a new JVC stereo and a Merta VT-GMOS-04 interface adapter for my birthday. I started having problems with my battery going dead in my truck after a day or two. I traced the problem to a short in the radio system. I sent the JVC unit in for repair and was told that there is nothing wrong with the unit, it may be in the adapter. I checked the reviews and read "Somebody needs to do something about this!" Written By unsatisfied customer, Poway, CA on Wednesday, May 28, 2008. Well, now there are two of us!!! What the fix for this?????

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Somebody needs to do something about this!

unsatisfied customer from Poway, CA on 5/28/2008

2003 Chevrolet Suburban
Crutchfield Customer Review (What's this?)

I see a trend here with these reviews. To start, I have been installing stereos for years. I'm on my second unit now. The first unit installed easily, piece of cake, no problems, that is until it began to drain my battery. Pain in the rear to troubleshoot this problem, and a pain having to recharge dead battery over and over again. Returned for another unit, free of charge of course. Easily installed second unit. Worked well for a while until, guess what, dead battery! At this point I could car less about another replacement. I'm looking for advice on how to install my $350 unit without OnStar, and without door chimes. All I need is the Bose amp and the head unit. Somebody out there, help!

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Metra GMOS-04 Wiring Interface

Mikey from Crestview, FL on 5/11/2008

2005 GMC Sierra 1500
Crutchfield Customer Review (What's this?)

Installed first until between a Kenwood DNX8120 and my 2005 GMC Sierra with Bose and Onstar. Followed instructions down to the wire (pun intended). Adjusted gain but could not get rid of horrible distortion and popping. Turning gain down just made the popping not as bad, but reduced the volume of the music unacceptably low. Crutchfield sent me a new GMOS-04. It behaved exactly as the first. Manufacture dates for both units is 6/07. To resolve my issue I bypassed the GMOS-04's RCA inputs. Basically my Kenwood's RCA outputs are now going straight to the truck's harness. WHAT A HUGE DIFFERENCE IN SOUND QUALITY AND VOLUME! It is like night and day. I feel bad for anyone who has installed this and now thinks that their new head unit or Bose system just aren't that great. This device robs the system of it's true potential in a very big way! For chime and Onstar I added an additional powered speaker (12 volt CB Speaker) to the front-left output of the GMOS-04 (white wires). If you have one of these, it is well worth the extra work and expense to take it out of the loop for audio!!!!

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Works for Me

Jake from Indianapolis, IN on 2/11/2008

2004 Chevrolet TrailBlazer
Crutchfield Customer Review (What's this?)

Great functionality for the price. Allows you to use Onstar, chimes and the factory 275 watt amp from Bose. I don't have the pop in the speakers like others reported. Just make sure you adjust the gain first, then the door chimes. Also, there is a typo in the directions. There is NOT an accessory wire for the 24 pin connector, only the 14. You will need to tape the interface box together.

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If you need this unit, you better buy it from crutchfield.

Gregg from State College, PA on 10/21/2007

2007 Chevrolet TrailBlazer
Crutchfield Customer Review (What's this?)

The first unit I hooked up, blew a transistor and caught fire. Luckily I smelled it, and got the unit out before it could do any harm. Crutchfield has THE best techsupport and return policy. They sent me out a brand new one, and paid for shipping of the old one back. The new adapter works great as long as you adjust the audio potentiometer. This is very important, or else you won't hear anything unless the volume is cranked up to 50, or the quality will be distorted. It's very easy to install, the hardest part is just getting your dash out. <BR><BR> Note: Don't be afraid to call the tech support, they know what they are talking about.

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Poor quality

Peter from Centreville VA on 9/19/2007

The item worked flawlessly for a week. I am using this with a DNX7100, which I love but the onset of cool mornings here has uncovered a problem. Everything powers up but there is no sound from any audio source, ipod, sat radio or FM. Within 5 minutes all of a sudden the sound will come back on. Based on the other reviews I would suspect a temperature sensitive defect with the GMOS-04 and not the HU itself. I have not reported this to customer service yet because I'm still trying to establish a pattern of when the problem occurs.

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Great! I don't know what all the fuss is about.

Mark from Pittsburgh, PA on 9/13/2007

2001 Chevrolet Monte Carlo
Crutchfield Customer Review (What's this?)

I ran into none of the problems the other reviewers ran into. As a matter of fact, it was a pretty cut and dry install. The best part of the adapter is it keeps the power on after the key is taken out of the ignition, just like it was when it was stock. It also has an adjustable volume for the audio going into the radio that helps take away any sound distortion. The adjustable door chime feature is nice as well. Overall, just read the directions and you're golden! Awesome accessory!

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Poor Quality - many issues

tmsco from Milltown,WI on 8/29/2007

Crutchfield Customer Review (What's this?)

Installed to 2005 GrandAM GT with monsoon amp and new Sony Gt610UI. Went through 3 units. First unit had mis-wired harness from factory crossing car data wire with 12v feed putting my car computer at risk. Second unit was bad and drained my battery overnight at random times drawing 1.5 amps instead of 30-50ma as designed when radio was off using RAP feature. Third unit worked power-wise but chimes didn't work properly. Crutchfield tech service was great and readily replaced units. Overall quality of unit is poor. Had to tape unit and connectors to hold it together and get good connections. Glad I purchased from Crutchfield as this would have been an expensive proposition from Metra.

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Stuck like Chuck

Big Luck from Washington, DC on 5/22/2007

2003 GMC Yukon

I have always enjoyed buying from Crutchfield. The time of delivery and the service are always exceptional. But this is one time that I regret a purchase. The GMOS-04 is not a very good product. From the very beginning it fell apart. Also, due to limited space behind radio's dash, it is very bulky to place. After the wiring, it would not immediately come on because of the loose connectors. Once installed, the sound was nice, but every other ignition start-up, receiver will be on but no sound will be produced. I have to shut down vehicle and start ignition several times until sound is produced. I don't see another product that will substitute the GMos-04, so I am stuck in this bad marriage.

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KEEP LOOKING

dave from HUDSON, IL on 3/31/2007

Crutchfield Customer Review (What's this?)

The title says it all......makes terrible popping noises in your speakers. I should have listened to the other reviewers of this products..... It was a very frustrating experience...caused me to return my $500 head unit also.

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Metra GMOS-04 Wiring Interface

josh from Florida on 1/22/2007

This adapter was not what I paid for. First of all, it made a very loud popping noise when i turned on the radio with the door open. It also added a lot of static and a squealing noise to the speakers. To top all of that off, it some how was draining my battery even while the vehicle was off and the stereo had no power. The adapter does keep the sound quality of my alpine head unit, though, when you can hear it over the squealing and static. Thankfully, crutchfield's great customer service is sending me a new one for free.

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Chevy Silverado w/ Bose

Sandy from Chatham, NY on 4/12/2006

2006 Chevrolet Silverado 2500/3500
Crutchfield Customer Review (What's this?)

Easy to install, but be sure to test before closing up since you'll almost certainly have to make some adjustments. Door chimes work fine, but little "beep" for memor set on seat doesn't work. Occasional "pop" when starting up. Sounds like when you power up an amp before the preamp.

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The GMOS-04 is okay

TK from South Bend, IN on 8/8/2005

2005 GMC Sierra 1500

I installed this unit in an '05 GMC 2500HD with the Bose 6-speaker system (no Onstar). I mated this unit with a Kenwood CDA-X889. The chime volume is no issue. As noted in a previous review the chime volume is adjustable. Set the level to your volume liking and you are good-to-go. When playing radio or CD's I do not get any feedback or popping from this unit. However, if I have either door open when I turn off the vehicle, and the radio is on, it makes a 'weird noice' from the speakers. Normally I shut the truck off first, then open the door. When done in this order the radio will continue to play until the door is opened, then it shuts off and no noise is made. For the most part this unit accomplishes what I needed it for. Could it be better - yes. Does it work the way it is - yes.

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Metra GMOS-04 Wiring Interface

Eric from Holdingford, MN on 4/22/2005

Crutchfield Customer Review (What's this?)

There are ups and downs with this piece. First off, the chime volume is adjustable, unlike noted in the other reviews, it's a simple dial on the inside of the unit. Negatives - 1. The unit does make popping noises through the speakers when I turn the vehicle off. 2. Onstar volume is not adjustable. Positives - 1. You do keep chimes and RAP (radio on until door opens). 2. Keeps Onstar. 3. Takes only 1 unit to keep Onstar and radio install, instead of two with all others.<BR>Overall - Metra/Axxess does not have this piece ready yet. I had it on backorder for 4 months because it wasn't ready, still isn't, wish they would have backordered it until it was right. If you need the piece it will get the job done, but if you can wait a little longer, do it.

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What to do

Mac from Dover DE on 3/31/2005

Crutchfield Customer Review (What's this?)

I bought this adapter and returned it. The chimes were way too loud and there was a popping sound in the right front speaker alone. It was not a grounding issue either. I called Metra myself and they basically could't help me. I wouldn't recommend this adapter. The good thing is that Crutchfield accepted my return without any hassles.

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Great sound quality for receiver, Poor chime and OnStar Sound

TR from Westlake Village, CA on 3/7/2005

Crutchfield Customer Review (What's this?)

The receiver I installed was the Alpine Iva-D901 in a 2004 GMC Sierra with the Bose System. The chime the Metra produces is much, much louder than the factory and is very irritating when it goes and goes and goes. There should be a level control to control how loud the unit rings at and you should also be able to turn it off. As well the OnStar works well at turning off the head unit and bringing up the OnStar voice however the voice is loud as well and you cannot control the volume as you could with the factory receiver. It also made random popping sound through the speakers, which wasn't a grounding problem. Also the box keeps coming apart, it has an upper piece and a lower piece and they keep seperating exposing the motherboard inside. I had to tape the thing together to hold it in place. The great thing about this product was the sound quality I am getting out of the factory system. The rca's on the Metra are high quality and gold plated transferring a better signal. I ended up cutting the wire that hooks up the OnStar and Chime sound because I couldn't stand the sound it makes. However when you do this the receiver loses its power, so I ran a knew power turn on lead. The loss of this is that you lose the extended turn on time when you pull the key out.

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Details

Hands-on research

Product Research

Features

Overview: The GMOS-04 interface is designed to let you replace the OEM radio with an aftermarket unit in amplified GM vehicles and retain full functionality of the OnStar system as well as all safety and warning chimes. The GMOS-04 will also retain the retained accessory power convenience features. This interface has the capability of adjusting chime and OnStar volumes as well. In addition to these features, the GMOS-04 has the required outputs for the installation of a navigation radio (including VSS, parking brake, and reverse outputs).

Vehicle Compatibility Chart: The GMOS-04 works in the following 2000-up GM vehicles.

MakeModelYear
BuickAllure2005-2009
Century2004-2005
Lacrosse2005-2009
Rainier2004-2007
Rendezvous2002-2007
Terraza2005-2008
CadillacEscalade2003-2006
ChevroletAvalanche2003-2006
Cavalier2000-2005
Corvette2005-2010
Express2003-2007
Impala2000-2005
Malibu2001-2004
Monte Carlo2000-2005
Silverado 2003-2007
SSR2003-2006
Suburban2003-2006
Tahoe2003-2006
Trailblazer2002-2009
Uplander2005-2008
Venture2000-2005
GMCEnvoy2002-2009
Savanna2003-2007
Sierra (Classic)2003-2007
Yukon/Denali2003-2006
HummerH22003-2007
H32006-2009
IsuzuAscender2003-2008
I-Series Pickups2006-2008
OldsmobileAlero2001-2004
Bravada2002-2004
Intrigue2002
Silhouette2000-2004
PontiacAztec2001-2005
Grand Am2001-2005
Grand Prix2004-2008
Montana2000-2005
Sunfire2000-2005
SAAB9-7x2005-2009
SaturnRelay2005-2007
Note: Please consult Crutchfield'sOutfit My Car for your specific vehicle and application.

OEM Steering Wheel Control Compatible (optional): The GMOS-04 features a right-angle 3.5mm connector that lets you keep your GM vehicle's OEM steering wheel controls via the optional Axxess Steering Wheel Control Interface (120ASWC1, sold separately).

Note: The GM vehicle must have factory steering wheel controls to retain access to the factory customization menu, once the factory radio is replaced with an aftermarket head unit.

OnStar and Chime Volume Adjustment: The volume is adjustable for both the OnStar output and the warning chime.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

to make it work[ JEFFREY  Sep 23, 2017 ]
A necessary item to get the job done easier.[ DOUG  Sep 20, 2017 ]
Easier hookup[ Charlie  Aug 25, 2017 ]
Required for the installation of my aftermarket radio.[ Christopher  Aug 24, 2017 ]
It was recommended for use with my 2007 Trailblazer SS with bose system w/o navi.[ Jon  Jul 23, 2017 ]
to retain factory chimes and alerts and hopefully connect to stock bose amp and speakers, we will see, recommended install kit[ Anthony  Jun 22, 2017 ]
I was referred to this product for my Pontiac. I installed an aftermarket radio, and my dash stops working and lights flash from traction control and other errors. Hoping this will help fix the problem.[ Jody  Jun 18, 2017 ]
the reviews looked and and im hoping its better than the pac. i received two pacs and there crap[ Thomas  Jun 04, 2017 ]
needed for the install on stereo[ brandy  Mar 20, 2017 ]
Better reviews[ Robert  Mar 11, 2017 ]
hope it will work[ William  Feb 27, 2017 ]
hey it beats cutting up the factory wiring harness for the head unit[ Ryan  Feb 16, 2017 ]
Crutchfield is a company that has been around for years i trust in their prouducts and in the crutchfield name.[ Michael  Feb 10, 2017 ]
Great price! And had a lot of good reviews![ Dakota  Jan 25, 2017 ]
the one in truck shorted out after low voltage and tried to remote start[ scott  Jan 13, 2017 ]
To connect my My aftermarket pioneer head unit to my bose system[ Benjamin  Oct 26, 2016 ]
Required[ Robert  Oct 24, 2016 ]
Needed it to for my stereo :-) [ patricia  Sep 14, 2016 ]
It's the he only kit try that retains my xm tuner in my Silverado.[ HENRY  Aug 03, 2016 ]
Needed for my 03 suburban bose system.[ Lucas  Jun 11, 2016 ]
For my 2008 Buick LaCrosse aftermarket stereo install[ Matthew  Jun 05, 2016 ]
Recommended and required.[ Christopher M.  Apr 23, 2016 ]
it was required for installation for my vehicle. My vehicle came with a factory bose amp[ ANDREW  Apr 03, 2016 ]
Recommend with stereo[ jeff  Mar 18, 2016 ]
For the Bose and On star compatability.[ Orlando  Mar 16, 2016 ]
You need it![ CASEY  Feb 28, 2016 ]
recommended by Crutchfield[ Jeff  Feb 25, 2016 ]
I choose this product because it would allow me to retain my factory amp[ gomezj22  Feb 22, 2016 ]
ability to integrate with the factory Bose system[ Joseph  Jan 12, 2016 ]
needed to install radio[ Mac  Dec 14, 2015 ]
Called Crutchfield and Advisor looked it up and told me this is the wiring harness I need for my truck[ Nathan  Dec 05, 2015 ]
Support Rep parker recommended it for my installation.[ sidekixx1  Dec 05, 2015 ]

9 questions already asked

You can check to see if this will fit your vehicle by using our Outfit My Car tool: http://www.crutchfield.com/car/carselector.aspxFor additional details on fit or installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on if this will fit and what you will need for an installation in your vehicle.[ Krissy  Jul 03, 2017 ]  Staff
You will want to contact an Advisor by phone (1-800-324-9695) or online chat to discuss compatibility with your factory system. They will be able to pull up your vehicle and see if this will integrate. If it does not, then they will also be able to discuss other options with you.[ Krissy  Jun 11, 2017 ]  Staff
Your radio can get power without the harness, but the harness makes the installation so much easier.[ D  May 02, 2017 ]
No. Not unless you cut and splice your factory harness which I would not recommend at all.[ PATRICK  May 02, 2017 ]
For additional details on fit or installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on if this will fit and what you will need for an installation in your vehicle.[ Kenny  Mar 04, 2017 ]  Staff
On the wiring harness is a level adjustment leave your door open and adjust it with door open it only Adjust the chime level with the door open close for to adjust music level[ TIM  Jul 03, 2015 ]
If you purchased the product from Crutchfield, feel free to contact our Tech Support team. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer. You can also post your question in our forums: http://community.crutchfield.com. Or try our online support center: http://crutchfield.custhelp.com/app/answers/list/kw/. [ Jeff  Jul 01, 2015 ]  Staff
Thank you![ Netcruizer99  Mar 16, 2015 ]
For details on fit or installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on if this will fit and what you will need for an installation in your vehicle.[ Krissy  Mar 16, 2015 ]  Staff
You will want to contact an Advisor by phone (1-800-324-9695) or online chat to discuss compatibility with your factory system. They will be able to pull up your vehicle and see if this will integrate. If it does not, then they will also be able to discuss other options with you.[ Krissy  Feb 27, 2015 ]  Staff
For details on installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on if this will fit and what you will need for an installation in your vehicle.[ Krissy  Apr 16, 2014 ]  Staff
The ability to retain steering wheel controls with aftermarket receivers will be determined by the receiver you are using and the vehicle you have. For full information on this type of integration (including the parts you will need) please contact an Advisor by phone or online chat.[ Jeff  Jan 06, 2014 ]  Staff
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