PAC C2R-GM11 Wiring Interface

Connect a new car stereo and retain RAP and safety warning chimes in select 2006-up General Motors vehicles

Item #: 127C2RGM11

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37 Reviews

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PAC C2R-GM11 Wiring Interface

PAC's C2R-GM11 radio replacement interface lets you replace the factory radio in select GM vehicles without OnStar, while retaining all factory warning chimes, Retained Accessory Power (RAP), and audible turn signal indicators. Warranty: 1 year.

Please enter your vehicle information or call a Sales Advisor at 1-888-955-6000 to find out if this model is compatible with your vehicle.

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.

PAC C2R-GM11 Wiring Interface Reviews

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37 reviews
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Cobalt head unit harness

Written By Redboxspider, Massachusetts on Monday, July 20, 2015

Crutchfield Customer Review (What's this?)

The wiring is color coded to match the after market radio , this stuff is pretty standard - Once you have this connected to the head units its just a plug and play to the Chevrolet wiring harness - The chime device has an on off switch, I left it on , the tone is lower and deeper than the original and didn't know until I used this device that my turn signal clicks came through the speakers .

Pros: No surprises , it worked and the wiring matched the after market unit

Cons: There were none .

Works good

Written By kirsten, Montana on Friday, March 13, 2015

Crutchfield Customer Review (What's this?)

Color coded made for an easy install. Door chimes and Blinker sounds work well, just make sure when installing behind the radio to face it with the speaker side towards the steering column or front towards the ignition shifter otherwise it is hard to hear the blinker.

Pros: Easy install.

Cons: Hard to hear the blinker when radio is on or windows are down but otherwise it does what it is suppose to do.

Awesome Product!

Written By Gary, 18040 on Friday, February 13, 2015

Crutchfield Customer Review (What's this?)

The PAC unit worked perfectly and install was a breeze. My door chime and turn signals work fine. I would recommend this to any one who is thinking about getting an after market head unit.

Pros: Easy install..Wires were color coded and made the install easy. Unit was small enough to tuck inside dashboard under new head unit.

Cons: None

Made installation super easy!

Written By Jack, Tulsa, OK on Sunday, January 18, 2015

Crutchfield Customer Review (What's this?)

This made the stereo installation very easy. Just strip a little insulation off the wires on this adapter and the radio harness, match up the colors, and crimp them together. It couldn't be easier! The tones and turn signal clicks that this unit puts out are pleasing. I'd use this one again!

Pros: Very very easy installation. Even if you have never installed a car stereo before, you can do this!

Cons: None

Delivers as-advertised results

Written By Justin A., Sanger, TX on Friday, December 26, 2014

Crutchfield Customer Review (What's this?)

Very easy installation, and allows retention of factory controls and chimes, as well as delayed shut-off (for when you turn off the ignition and the radio stays on until the door opens). Can't beat it for the price.

Pros: Easy to install, takes the place of the scoche-style harness.

Cons: A little lacking in the instructions, but fairly intuitive nonetheless.

Everything works as if factory installed

Written By StephenB, Wichita, KS on Tuesday, November 18, 2014

Crutchfield Customer Review (What's this?)

Everything worked as it should like the factory unit. The subwoofer was configureable and everythign else worked like a factory install.

PAC C2R-GM11 Wiring Interface

Written By Anonymous, Vallejo, CA on Friday, October 03, 2014

Crutchfield Customer Review (What's this?)

Works well

Pros: Easy install

Cons: Thought the chimes would play through the speakers


Written By Waffle, Frederick, MD on Sunday, June 22, 2014

Crutchfield Customer Review (What's this?)

Simple to use and very necessary.

Pros: It's ease of understanding.

Cons: None.

PAC C2R-GM11 Wiring Interface

Written By Steve, Skokie, Il. on Thursday, April 03, 2014

Crutchfield Customer Review (What's this?)

Wired in simple and works great an i still have my turn signal noise and head lamp on chimer,

Pros: easy install and needed.

Cons: None

My 2006 HHR

Written By Ray729Fl, Pompano Beach on Sunday, March 16, 2014

Crutchfield Customer Review (What's this?)

The instructions provided were in detail and easy to understand. All attribute that apply to the vehicle were duplicated as far as alerts.

Pros: Ease and simplicity of installation certainly is a help.

Cons: Not applicable.

Adapter Works As It Should

Written By TimH, Nashville, TN on Wednesday, March 05, 2014

Crutchfield Customer Review (What's this?)

Absolutely necessary. Everything works as it should and just as it did with the factory head unit.

Pros: Perfect integration with my car. Great website, good support and documentation made this easy to install.

Cons: None

works just not very loud.

Written By james'customHHR, Fort Wayne, IN on Monday, March 03, 2014

Crutchfield Customer Review (What's this?)

it does what it's supposed to do which is expected the only downfall is its not that loud and if you have your music at normal listening volume you cannot hear your turn signals are on or doors open or anything like that but it does keep you legal and does what it's supposed to this all that concerns me for this item.

Pros: keeps you legal.

Cons: Volume is to low and price is to high

PAC C2R-GM11 Wiring Interface

Written By Spencer, Texas on Thursday, February 20, 2014

Crutchfield Customer Review (What's this?)

Great buy if you need to keep factory controls


Written By TC, San Antonio TX on Saturday, December 28, 2013

Crutchfield Customer Review (What's this?)

Hooked up OK but you can't hear the turn signals any more.

PAC C2R-GM1 Factory Integration Adapter

Written By J.R.Gurney, Geneva,Fl. on Wednesday, December 25, 2013

Crutchfield Customer Review (What's this?)

Dealing with Crutchfield is always the best. They said I needed the PAC C2R-GM1 for my steering controls to work a turn sig. to be heard and would give a great deal if ordered with radio. Very easy to install when doing radio it was a no brainier not to. Works very well. Thanks Crutchfield

Pros: All Good

Cons: None


Written By KJ, Portland, OR on Wednesday, October 30, 2013

Crutchfield Customer Review (What's this?)

The blinker sound is so faint, It's impossible to hear with the radio on or a window open, I like hearing my blinkers, We all hate when people drive with their blinkers on, because they cant hear them. And the ding when I open my door is so loud its horrible. All the sounds comes from the little blue box, once that is behind your radio and dash, Forget about hearing anything.

Pros: Easy to install


Factory adaptor

Written By Joe Joe, Mechanicsburg, PA on Monday, October 21, 2013

Crutchfield Customer Review (What's this?)

Works great. Does what it was intended for.

Pros: Easy install

Cons: Non

New Sounds

Written By Mike, Acworth, GA on Tuesday, September 03, 2013

Crutchfield Customer Review (What's this?)

There must of been a short in the old one because my car makes sounds I did not remember hearing! lol Reminder bells, turn signals

Must have

Written By CurtB, Lacey, WA on Friday, August 16, 2013

Crutchfield Customer Review (What's this?)

Was easy to install and all factory options are working as they should.

Pros: Is a must have for some vehicles.

Cons: Pricey even at half price.

Keeps all chimes and warnings

Written By BillT, Maple Hts, OH on Sunday, August 11, 2013

Crutchfield Customer Review (What's this?)

Without a doubt this is need when upgrading to an third party radio in many GM cars. Easy to wire into the harness and works perfectly.

Pros: All warnings are still audible when using this unit.

Cons: Could be just slightly louder but it's still able to be heard.

PAC C2R-GM11 Wiring Interface

Written By Mark & Chris, Melbourne, FL on Saturday, July 20, 2013

Crutchfield Customer Review (What's this?)

Worked perfectly on an '06 HHR to adapt a JVC KW-R900BT and iDatalink Maestro ADS-MSW. Did require one undocumented wiring change to supplied harness to use the Maestro, but exactly as directed otherwise. Made installation simple, with no changes to factory harness required. Chimes and turn signal sounds work through adapter as intended.

Pros: Simplified installation.

easy intall

Written By tim, lewiston id on Friday, July 05, 2013

Crutchfield Customer Review (What's this?)

made installation of my new equipment very easy, and retained all the vehicle warning sounds.

Pros: easy install

PAC C2R-GM11 Wiring Interface

Written By Daryl, Elma ny on Sunday, June 30, 2013

Crutchfield Customer Review (What's this?)

Made installation very easy

PAC C2R-GM11 Wiring Interface

Written By Anonymous, Erie,PA on Saturday, June 08, 2013

Crutchfield Customer Review (What's this?)

Works as described

worked without a hitch

Written By Anonymous, San Diego, CA on Monday, June 03, 2013

Crutchfield Customer Review (What's this?)

I like most people, did not want to spend extra money on an adaptor, but GM routes a lot of warning sounds through their factory radios. Crutchfield gave it to me at a discount when I bought a receiver. Hooked up easy with color coded wires that matched my receiver output harness wire ends. I did this on my kitchen counter with good light and used the posi-twist connectors. The 2 pre-attached outputs from the adaptor snapped into the 2 from the vehicle, and I then easily installed the head unit in my car without doing wiring connections in the vehicle.

Pros: tailored made for my car, straight forward install, works great.

Cons: none, except GM shouldn't force one to have to buy an adaptor in the first place with this type of design.

Just as described

Written By Timothy, Mississippi on Wednesday, April 03, 2013

Crutchfield Customer Review (What's this?)

Just as it says plug and play all you have to do is wire your radio wires to this harness then plug into car and into radio and your done. For 99 dollars i got what i payed for and it works perfect.

Pros: Works perfectly

Cons: Was 99 dollors and you have to make sure its as close to your dash by radio or its hard to hear.

GM radio Integration Adapter

Written By ES, PA on Sunday, March 17, 2013

Crutchfield Customer Review (What's this?)

Product works as described. Pretty much plug and play with a few wire crimps.

Pros: Chimes working for the first time in a year.

Cons: Price of component. This much for a box that makes chimes. I got mine for half price, which was still slaty for what it does.

It worked

Written By Ben S, Searcy, AR on Sunday, March 10, 2013

Crutchfield Customer Review (What's this?)

I hate that a adapter like this has become needed in new cars but it has. I will say that it was easy to hook up and it worked as it should so no complaints there. I just wish that it wasn't needed lol.

Pros: Works perfect

Cons: Seems like it should not be needed but the nature of the beast I guess

PAC C2R-GM11 Wiring Interface

Written By DonS, Fort Pierce,Fl on Thursday, September 27, 2012

Crutchfield Customer Review (What's this?)

A little skeptical reading reviews about Turn Signal sounds. Works like charm and sound is fine. very satisfied

Pros: Works as advertize!!

Cons: Needs a peel and stick tape to anchor unit

Easy to install but hope you dont care about audible turn signal

Written By Justin, Dixon, IL on Saturday, March 03, 2012

Crutchfield Customer Review (What's this?)

Kind of wish I didn't have to waste money on this. If you're not great at keeping an eye on your turn signal when switching lanes you may be in for some trouble. If you don't turn enough to automatically turn off your turn signal you won't be able to hear the audible clicking reminding you your turn signal is still on.

Pros: Get to keep factory chimes. Easy to install.

Cons: When you install this your Audible turn signal no longer plays through the front driver speaker. It will now play through this exact box and it is extremely quiet. If I have my deck up half volume I can't even hear it anymore. Seems pretty expensive for what it does.

It works

Written By travis, durham nc on Monday, February 20, 2012

Crutchfield Customer Review (What's this?)

Works fine in a 2006 chevy hhr..

Pros: works (i guess, if you have the radio turned down), easy to install

Cons: not sure why its needed, its so quiete and not the same sound almost feel like i was possibly wasted my money... Sound comes from that little blue box now, not the speakers anymore, and the wires were so short its impossible to get it closer to the driver, must be stuffed behind the radio, would work great if you could get it all the way to the B pillar right beside the drivers ear.

It works. What more can I say?

Written By Patrick G, Glendale, AZ on Monday, March 21, 2011

Crutchfield Customer Review (What's this?)

I bought this along with my Kenwood deck. Install was easy enough as it includes the wiring harness kit to hook up to my 2009 cobalt.. few minutes of strip and crimp and its good to go.

The first unit I recieved had a malfunction I guess.. everytime I used my turn signals the radio would lose power and the signal chimes would cut out. After 3 or 4 calls to tech support we tried a few things, and identified it was a faulty interface. They sent me a new unit which I have now installed and it works beautifully.

Everyone of the guys at Tech support I talked to were professional and courteous.. so much in fact that because of them, it is doubtful I will buy a car stereo, or any mobile electronics for that matter, from anyone else other than Crutchfield from now on. Kudos.

PAC C2R-GM11 Wiring Interface

Written By Jeremy, Pittsburgh, PA on Tuesday, February 08, 2011

Crutchfield Customer Review (What's this?)

2008 Pontiac G5 base model. Had my old Pioneer that i loved and wanted to expand the audio over time. Was obvious the factory head had to go!

Yes the reviews are right the turn signal chime or click or what ever is a bit weak sounding.
Depending how you "stuffed" or mounted the box behind the head unit depends on how loud the seat belt warning is.

I heard and read plenty of forums and sites claiming there are cheap harnesses available but I knew that this was the correct route to go. Why chance screwing anything up. Yes a bit pricey, But Crutchfield advisors were a HUGE help and this unit is awesome. Go cheap, pay in the end, do it right the first time.
Buy the

easy to install

Written By Lisa, chicago, il on Tuesday, September 29, 2009

I bought this for my 2008 cobalt and I am glad I did. It was quick and easy to set up and it worked with my car. The only thing I do not like is that the turn signals sound different, but I am glad that I still have the factory sounds.

PAC C2R-GM11 Wiring Interface

Written By Tom, Poughkeepsie, NY on Tuesday, August 11, 2009

Crutchfield Customer Review (What's this?)

Did not work for my 2008 Cobalt. I had it professionally installed with my new double din head unit, and he said the chime box didnt work at all. He had to cut it all up to get to just the wires he needed.

PAC GM Radio Integration Adapter

Written By Ron, wa state on Tuesday, February 24, 2009

Crutchfield Customer Review (What's this?)

Works great in a 2006 HHR made the install really easy........

PAC C2R-GM11 Wiring Interface

Written By Perry, Jax, FL on Friday, September 26, 2008

Crutchfield Customer Review (What's this?)

Aside from the time it took to connect this to the radio harness, it made the install really easy. Hardest part was finding a place to tuck the unit in to the dash behind the radio. All the chimes work but the blinker sound is a bit low in volume.

Hands-on research

What's in the box?

Download owner's manual

  • GM radio replacement interface
  • OEM to interface adapter harness
  • Installation instructions

Product Research


Overview: The PAC C2R-GM11 Radio Replacement Interface allows easy connection of an aftermarket stereo in select General Motors vehicles; please see "Outfit My Car" to confirm compatibility. This interface provides connections for the new radio's power, illumination, and speaker leads. With the C2R-GM11, the new radio will replicate all factory chimes and audible turn signals. It also provides a data bus generated 12 volt accessory output, so the factory RAP system remains intact (Retained Accessory Power, RAP, keeps the radio powered after the key is removed from the ignition until the driver's door is opened, or ten minutes passes, whichever comes first).

Steering Wheel Controls: If your vehicle has steering wheel controls (and the aftermarket radio is compatible) they can be integrated using the optional PAC SWI-RC steering wheel control interface (541SWIRC, sold separately).

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.

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