Chat
Contact us
Close contact box
Connect ID #
994 551 828 4
Connect ID #
994 551 828 4
Don't wait on hold. We'll call you back when it's your turn to talk with the next available .
Please enter your name  
Please enter your phone number  
Please enter a message  

Calls may be recorded for training and quality control purposes.

We are located in Virginia USA.

Thank you. We will be calling you .
We're sorry. We have encountered a problem.

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

Item # 120GMOS04

Metra's GMOS-04 GM radio replacement interface lets you replace the factory radio in select OnStar-equipped 2000-up...

Find what Fits your vehicle

Remove

Checking fit...

Metra's GMOS-04 GM radio replacement interface lets you replace the factory radio in select OnStar-equipped 2000-up...

California customers:
Please click here for your Proposition 65 warning.

24 questions - 34 answers

Item # 120GMOS04

About the Metra GMOS-04 Wiring Interface

Charlie Pastorfield
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.

READ LESS

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
MFR #GMOS-04

Customer reviews for Metra GMOS-04 Wiring Interface

Loading reviews...

Average review:

4.0 out of 5 stars
323 reviews

Thanks for submitting your review

Filter by rating

Customer photos

Customer provided image, click to load a larger version.
Customer provided image, click to load a larger version.

Sort reviews

Sort by:
Items per page:
View page:

Verified customer (What's this?)
Verified employee review (What's this?)

Reviewed on Samsung.com

This review was collected as part of a promotion

Pros:

Cons:

Crutchfield response
Customer provided image, click to load a larger version.
<< >>

More details on the Metra GMOS-04 Wiring Interface

Stacey B.
The Metra GMOS-04 Wiring Interface replaces these items:

Product Research

Features

Radio Replacement Interface: 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.

Make Model Year
Buick Allure 2005-2009
Century 2004-2005
Lacrosse 2005-2009
Rainier 2004-2007
Rendezvous 2002-2007
Terraza 2005-2008
Cadillac Escalade 2003-2006
Chevrolet Avalanche 2003-2006
Cavalier 2000-2005
Corvette 2005-2010
Express 2003-2007
Impala 2000-2005
Malibu 2001-2004
Monte Carlo 2000-2005
Silverado 2003-2007
SSR 2003-2006
Suburban 2003-2006
Tahoe 2003-2006
Trailblazer 2002-2009
Uplander 2005-2008
Venture 2000-2005
GMC Envoy 2002-2009
Savanna 2003-2007
Sierra (Classic) 2003-2007
Yukon/Denali 2003-2006
Hummer H2 2003-2007
H3 2006-2009
Isuzu Ascender 2003-2008
I-Series Pickups 2006-2008
Oldsmobile Alero 2001-2004
Bravada 2002-2004
Intrigue 2002
Silhouette 2000-2004
Pontiac Aztec 2001-2005
Grand Am 2001-2005
Grand Prix 2004-2008*
Montana 2000-2005
Sunfire 2000-2005
SAAB 9-7x 2005-2009
Saturn Relay 2005-2007

Note: Radio information through the factory HUD (Heads-Up Dispaly) will be lost after installing an aftermarket radio, but vehicle information will still be retained.

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.

Loading accessories...

Customer Q&A

24 questions already asked

Q
Will I need an inline output converter for 2004 gmc sierra with Bose audio system?
jeb  Feb 14, 2023
1 answer
A
Greetings Jeb, and thank you for your question. I will assume you are replacing the GM radio with an aftermarket stereo in this case. You will not need an additional line output converter with the 2004 Sierra.
hogan  Feb 14, 2023 (Staff)
Q
Will this work on my 2003 Chevy Trailblazer LTZ with Bose and onstar?
landon  Feb 26, 2022
1 answer
A
It worked fine for my 2004 GMC Envoy SLT with Bose.
caleb  Feb 26, 2022
Q
Do I have to have steering wheel interface? Have a 2006 Trailblazer
tiffany  Feb 25, 2021
2 answers
A
You don't have to if you don't need to have steering wheel contols on the new unit. I never have on all the new head units I've put in.
scott  Feb 25, 2021
A
If you don't mind your steering wheel buttons not working. I suppose you could put that under personal preference.
christopher  Feb 25, 2021
Q
I'm taking out factory stereo with aftermarker pioneer, it has factory bose, and I'm gonna run a amp to double subs..in 2003 trailblazer..will this harness work?
eugene  Dec 23, 2020
1 answer
A
Yes it should work just fine ! I thought I had gotten the wrong one but ,I had just forgot to put a wire together. Does what it needs to do
ignacio  Dec 23, 2020
Q
Does the wiring harness come fully assembled when you purchase the radio?
cole  May 27, 2020
2 answers
A
Bruce is correct! You can find more information on our ReadyHarness service here: www.crutchfield.com/p_264PASCON/item.html
jason  Jun 20, 2020 (Staff)
A
No. I also purchased Crutchfield's ReadyHarness Service to complete the build.
bruce  Jun 11, 2020
Q
Installed on my 2005 Chevy Silverado have power but no sound. Put stock radio back in and everything works. Has anyone ran into this before?
joseph  Apr 18, 2020
1 answer
A
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.
kristina  Apr 30, 2020 (Staff)
Q
Will this work on my 2006 chevy trailblazer LT with bose and onstar?
silentbill  Jan 22, 2020
2 answers
A
You can check to see if this will fit your vehicle by using our Outfit My Car tool: http://www.crutchfield.com/car/carselector.aspx 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.
kristina  Feb 06, 2020 (Staff)
A
I purchased this same product for my 2003 Chevy Avalanche with Bose and OnStar and it worked fine. I still had my chimes and everything
rodney  Jan 22, 2020
Q
Will this work in my 2006 chevy trailblazer LT with bose and on star?
silentbill  Jan 22, 2020
1 answer
A
I used it in my 05 Trailblazer with the same system
james  Jan 22, 2020
Q
What do you do if your aftermarket radio doesnâ??t receive power I have a 2002 Pontiac grand am and I have it all wired up exactly how it goes but doesn't want to power it?
travis allen  Sep 25, 2019
1 answer
A
Hi Travis, sorry to hear you're having trouble with your stereo. It will be hard to even give a good guess on what could be going on with that stereo. Did you purchase your gear from us here at Crutchfield? If you did make your purchase from us, our tech support team will be more than happy to go over everything with you, perform troubleshooting, and find the solution that will get your stereo up and running. You will find their number listed online when you log into your account, or it can also be found with the invoice/shipping confirmation email we would have sent you. If you did not purchase your gear from us, I suggest contacting technical support of the company you worked with, or the manufacturer of your stereo. If nothing can be found through those channels, you may need to speak with a local stereo installer, or mechanic in your area.
jessica  Oct 09, 2019 (Staff)
Q
Will this allow me to hook aftermarket radio and subwoofer in a 2002 gmc envoy with bose sound system?
jacob  Jul 18, 2019
2 answers
A
It should I it worked perfect in my 02 trailblazer
frankie  Jul 19, 2019
A
Yes I used it in my 07 Trailblazer ss with bose
chris  Jul 18, 2019
Q
i have a 2004 gmc envoy xuv with bose system with amp and onstar i got 2 different wiring harnesses connected everything and the radio has power but there is no sound from the speakers at all would this harness work?
richard  May 04, 2019
1 answer
A
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.
kristina  May 14, 2019 (Staff)
Q
Will this work on a 2004 Sierra Denali with luxury Bose amplified sound system?
l  Feb 06, 2019
2 answers
A
Yes it should it worked on my Silverado with the Bose amp abs speakers
scott  Feb 08, 2019
A
Your product adviser can answer this question, but I myself, will say yes. I have a 2009 HUMMER H3 Luxury Bose amplified system in it and also the OnStar system, although I don't use the OnStar. Very easy to install, but be sure to read the settings instructions as they have two different ways to set the sound of the door/warning chimes and a different way to set the volume for the stereo audio.
darren wesley  Feb 06, 2019
Q
will this work on a 2008 gmc envoy with bose?
frank  Dec 11, 2018
3 answers
A
I don't know about a 2008 Envoy. It worked on a 2006 Silverado.
britt  Dec 12, 2018
A
Yes is a must
angel  Dec 12, 2018
A
yes this should work on your 2008 bose system
nickolas  Dec 11, 2018
Q
Can this kit be used to add aux 3.5 jack to an Envoy factory radio?
ty  Dec 05, 2018
1 answer
A
This harness is used to install a new radio into a compatible vehicle. The 3.5mm plug is meant to work with the ASWC-1 steering wheel radio control interface. However, we might have an adapter to give your vehicle an aux audio input. I recommend contacting an advisor on 1-800-324-9695 to check for an aux input adapter My Bio: https://www.crutchfield.com/bio/Paul
jason  Dec 12, 2018 (Staff)
Q
Will this retain my monsoon amp on my 2002 Pontiac grand am?
carmen  Feb 20, 2018
1 answer
A
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.
kristina  Mar 01, 2018 (Staff)
Q
Will this fit a 2004 Grand Prix GT2 with the monsoon sound system and steering wheel controls? I am trying to install a Pioneer AVH-290BT double din radio. Thanks
kyle dean  Jul 02, 2017
1 answer
A
You can check to see if this will fit your vehicle by using our Outfit My Car tool: http://www.crutchfield.com/car/carselector.aspx 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.
kristina  Jul 03, 2017 (Staff)
Q
Will this also maintain functionality of rear dvd entertainment system?
anthony  Jun 11, 2017
1 answer
A
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.
kristina  Jun 11, 2017 (Staff)
Q
Will my new radio still get power without the harness?
ricky  May 02, 2017
2 answers
A
Your radio can get power without the harness, but the harness makes the installation so much easier.
david  May 02, 2017
A
No. Not unless you cut and splice your factory harness which I would not recommend at all.
patrick  May 02, 2017
Q
Will it work on a 06 monte carlo ?
mikey  Mar 04, 2017
1 answer
A
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.
kenneth  Mar 04, 2017 (Staff)
Q
I have the GMOS-04 connected today and all is well. I want to bypass the BOSE amp, install new amps and speakers, but maintain the chimes. If my head unit has the RCA's for the new amps (bypassing the BOSE), how can I wire this so the chimes still work, but don't get amp'd to some huge level like my speakers? Thanks, Jim A
jim  Jun 30, 2015
2 answers
A
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
A
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)
Q
I have a 2006 Corvette coupe with Bose (but no Onstar) and am wondering if this product will maintain the current Sirius/XM receiver or if I have to buy a new Sirius/XM receiver?
david  Mar 15, 2015
2 answers
A
Thank you!
david  Mar 16, 2015
A
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.
kristina  Mar 16, 2015 (Staff)
Q
Will this harness connect the OnStar mic to the new head unit, or do I need to install the 2nd mic that came with the unit?
dennis w.  Feb 26, 2015
1 answer
A
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.
kristina  Feb 27, 2015 (Staff)
Q
Will this work on my vehicle, 2003 Chevy Tahoe with Bose system? I do not have OnStar or steering wheel controls.
jeremy  Apr 16, 2014
1 answer
A
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.
kristina  Apr 16, 2014 (Staff)
Q
do I need another adapter to keep the steering wheel control on my 2004 Pontiac Grand AM with monsoon amp?
john c  Jan 05, 2014
1 answer
A
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)
SHOW MORESHOW LESS

Loading articles...

Compare the sound