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Metra GMRC-03 Wiring Interface

Install a new car stereo and retain the factory door chimes and audible safety warnings in 1996-04 Cadillac vehicles

1 Review

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Item # 120GMRC03

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Our take on the Metra GMRC-03 Wiring Interface

Metra's GMRC-03  wiring interface lets you replace the factory radio in select 1996-04 Cadillac vehicles without premium audio systems or OnStar®, while retaining use of all factory warning chimes. Warranty: 1 year.

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:

  • GMRC-03 Cadillac Class II Data Bus interface
  • Wiring harness with 2" wide 32-pin blue plug on one end and a 7/8" wide 10-pin white plug on the other end
  • Installation instructions

Metra GMRC-03 Wiring Interface Reviews

Average Customer Review(s):

(1 Review)

Does not work for cadillacs

Chris from Las Vegas Nevada on 8/16/2011

Crutchfield Customer Review (What's this?)

This does not even deserve the 1 star that I am giving it. It does not work in Cadillacs. It screws up the battery,(car goes dead overnight), The alarm system,and messes with onboard diagionstics. I Called Metra and there fix is to rewire the stereo and remove the rear seat and rewire the power door lock relay. Great news for a part that supposed to fix the aftermarket head unit install. A waste of good money!




Hands-on research

Product Research


Overview: The Metra/Axxess GMRC-03 is designed to interface an aftermarket stereo with the factory audio system in select Cadillacs that do not have OnStar or amplified systems. It will retain the warning chimes that are lost when the factory radio is removed. The interface also provides a 12-volt switched accessory output for proper radio operation.

Note: The GMRC-03 can be used in Cadillacs with a factory amplifier, however the factory amp must be bypassed, and the speaker wires on the GMRC-03 must not be used. Running new speaker wires is recommended. If the Cadillac also has OnStar, that feature will also be lost. (Cadillacs with amplified systems and OnStar should use the GMOS-06 interface.)

Compatibility: The GMRC-03 is compatible with the following Cadillacs:

  • 1999-2005 Deville
  • 1999-2002 Eldorado
  • 1999-2004 Seville

Retained Accessory Power (R.A.P.): The ignition power source of the Cadillac keeps the radio on until one of the doors is opened. This feature is called the R.A.P. (retained accessory power). The GMRC-03 is designed to retain this feature.

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