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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
Item # 120GMOS04 | MFR # GMOS-04
$84.99 Earn up to 85 Rewards points
Our take on the Metra GMOS-04 Wiring Interface by Crutchfield's 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.
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.
Metra GMOS-04 Wiring Interface Reviews
Average Customer Review(s):
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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.
Note: Please consult Crutchfield's Outfit 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.
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Why did you buy this?
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 ]
8 questions already asked
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
2 answers 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 ]
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