Metra VT-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

Item #: 120GMOS04

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199 Reviews

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Metra's VT-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, then check here for a list of parts. You can also call an Advisor for more information.

Metra VT-GMOS-04 Wiring Interface Reviews

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Important installation component

Written By OllieS, Longview, TX on Wednesday, May 20, 2015

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

Written By LesS, Michigan on Monday, May 04, 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 VT-GMOS-04 Wiring Interface

Written By Anonymous, Granite City, IL on Sunday, April 12, 2015

Crutchfield Customer Review (What's this?)

Easy to install. Was very pleased

Thanks Crutchfield

Written By JR, Iowa on Thursday, March 26, 2015

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

Written By Jerry K, Minnesota on Thursday, March 19, 2015

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!

Metra VT-GMOS-04 Wiring Interface

Written By TKS, North Carolina on Wednesday, March 11, 2015

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

Written By Jason1, Agana, Guam on Saturday, February 28, 2015

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

Written By Troprice, Texas on Saturday, February 28, 2015

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

Written By bigjohn, ga on Thursday, February 26, 2015

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

Written By Kim R, Chicago Illinois on Thursday, January 15, 2015

Crutchfield Customer Review (What's this?)

Just as advertised

Pros: Chime sounds cheap

Cons: Works perfectly

Metra VT-GMOS-04

Written By Ben, Harlingen, Tx on Tuesday, January 13, 2015

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

Written By John C, Arkansas on Saturday, January 10, 2015

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.

Best option on the market

Written By John T, Hampton, VA on Monday, December 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

Written By Anonymous, Tennessee on Sunday, December 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 VT-GMOS-04 Wiring Interface

Written By Anonymous, NY on Sunday, December 28, 2014

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

Written By Rj, Sunshine state on Friday, November 28, 2014

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


Written By Brotherwind, T or C NM on Thursday, November 13, 2014

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 VT-GMOS-04 Wiring Interface

Written By Anonymous, Rockland, MA 02370 on Tuesday, November 11, 2014

Crutchfield Customer Review (What's this?)

Really made installation easy.

Didnt work

Written By Charlie, Mt on Wednesday, November 05, 2014

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.

Metra VT-GMOS-04 Wiring Interface

Written By Bdubtex, Memphis, TN on Thursday, October 02, 2014

Crutchfield Customer Review (What's this?)

Works great

2007 Chevy Silverado 1500 with Bose

Written By Anonymous, Illinois on Friday, September 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

Written By Paul, Houston, TX on Wednesday, September 24, 2014

Crutchfield Customer Review (What's this?)

It works and easy to install.

Metra VT-GMOS-04

Written By Jorge, Haines City, Florida on Friday, September 19, 2014

Crutchfield Customer Review (What's this?)

Plug and play, no issues

Cons: Too bulky

Good Product

Written By DCP, Houston, TX on Tuesday, September 02, 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

Written By KellyK, Georgetown, Tx on Thursday, August 28, 2014

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 VT-GMOS-04 Wiring Interface

Written By Anonymous, Roanoke Va on Wednesday, August 06, 2014

Crutchfield Customer Review (What's this?)

Was not a good unit

5 stars!

Written By Wyatt, Edgerton, MN on Saturday, August 02, 2014

Crutchfield Customer Review (What's this?)

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

Pros: Easy install

Wiring harness

Written By MikeH, Tulia, TX on Saturday, July 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

Written By zbee062, Anderson, SC on Tuesday, July 22, 2014

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 VT-GMOS-04 Wiring Interface

Written By Anonymous, Lexington, Kentucky on Monday, July 14, 2014

Crutchfield Customer Review (What's this?)

Very complicated with poor instructions

Nice unit

Written By Anonymous, Lincoln Ne on Tuesday, July 01, 2014

Crutchfield Customer Review (What's this?)

Straight forward wiring

Does what it's supposed to do...

Written By S, Kansas City on Tuesday, June 03, 2014

Crutchfield Customer Review (What's this?)

Works perfectly in my 2002 GMC Envoy.

Works with a little intervention.

Written By Allen E., Oswego, IL on Monday, April 28, 2014

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 VT-GMOS-04 Wiring Interface

Written By Anonymous, sonora, Tx on Monday, April 21, 2014

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?

Crutchfield response on Wednesday, April 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

Written By MisterBond1989, Adelanto on Thursday, April 10, 2014

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

Written By JYaz, Hanover, PA on Thursday, April 10, 2014

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

Written By Doug H, Charleston S.C. on Tuesday, March 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

Written By David, Fremont, NC on Sunday, March 09, 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


Written By Dahveed18, Flint, MI on Sunday, March 09, 2014

Crutchfield Customer Review (What's this?)

Simple to use!

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

Cons: None

Metra VT-GMOS-04

Written By Sean P, Southern California on Saturday, February 22, 2014

Crutchfield Customer Review (What's this?)

Plug and Play, worked well

Pros: easy install

Cons: needs second cable for steering wheel

Worked well

Written By CCVirginia, Fairfax, VA on Tuesday, February 18, 2014

Crutchfield Customer Review (What's this?)

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


Written By aditaa, Austin, TX on Saturday, February 08, 2014

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

Written By Lox4rox, Texas on Sunday, February 02, 2014

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

Written By JT, Bosque Farms, NM on Saturday, January 25, 2014

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

Written By Jeff M, San Antonio, TX on Friday, January 03, 2014

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.

Unit works, instructions horrible

Written By Steve KY, Ashland KY on Friday, January 03, 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

Written By Matt, Milwaukee, WI on Friday, January 03, 2014

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 VT-GMOS-04 Wiring Interface

Written By Anonymous, Lansing, Mi on Sunday, December 22, 2013

Crutchfield Customer Review (What's this?)

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

Perfect for GM with Bose

Written By EA, El Segundo CA on Thursday, December 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

Written By Ross, Chesapeake, VA on Friday, December 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

Written By Drock77, Claremore, Ok on Tuesday, December 03, 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 VT-GMOS-04 Wiring Interface

Written By Anonymous, Aurora IL. on Saturday, November 30, 2013

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.

great quality product.

Written By richie o., bronx ny on Saturday, November 23, 2013

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

Written By jasonsfn, Sacramento, CA on Sunday, November 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

Written By Anonymous, Sussex, WI on Thursday, November 07, 2013

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.

Written By Dirk A, Jonesboro, AR on Wednesday, November 06, 2013

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 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

Written By Ray S, Sandwich Il on Sunday, November 03, 2013

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

Metra VT-GMOS-04 Factory Integration Adapter

Written By Jack, Castro Valley, CA on Thursday, October 31, 2013

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 Sunday, November 03, 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

Written By Mike F, Fort Worth, TX on Monday, October 28, 2013

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

Written By chefjoey, woodridge, il on Saturday, October 26, 2013

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.

Written By Pasquale M., Massachusetts on Thursday, October 24, 2013

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 VT-GMOS-04 Wiring Interface

Written By DarrellD, San Antonio, TX on Friday, October 11, 2013

Crutchfield Customer Review (What's this?)

This harness worked flawlessly

Metra VT-GMOS-04 Wiring Interface

Written By d500, Independence, KY on Wednesday, October 02, 2013

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

Worked right out of the box.

Written By Trevor, Albert Lea, MN on Monday, September 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

Written By Steve D, California on Thursday, September 05, 2013

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

Written By JimM, Greenville, NC on Tuesday, September 03, 2013

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

Written By Anonymous, Lutz florida on Thursday, August 29, 2013

Crutchfield Customer Review (What's this?)

Great part thank Crutchfield

Pros: Easy installation

Cons: Non

Metra VT-GMOS-04 Wiring Interface

Written By Anonymous, Franklin, Tn on Thursday, August 22, 2013

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

Integration Kit

Written By Awt2b!, Seattle, WA on Monday, August 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!!

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

Written By Soldier meister, Pasadena, CA on Friday, July 26, 2013

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

Written By Angelo, Virginia Beach, VA on Tuesday, July 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!

Written By Joe S., Lowell, MI on Saturday, July 13, 2013

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 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" 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 VT-GMOS-04 Wiring Interface

Written By Anonymous, Indianapolis, IN on Friday, July 12, 2013

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.

Written By Michael, Independence,MO on Wednesday, July 10, 2013

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.