2002 Grand Am Stereo Install Problem

[grizzlyaddams]

For starters, I have installed probably about 20 Aftermarket stereos and also several amps and subs, including installing the amp wiring from bay to trunk so I at least have an idea what I'm doing.

I attempted to install an aftermarket Pioneer head unit in my girlfriends 2002 Pontiac Grand Am. After completing the wiring, the head unit would not power on. I am using Scosche GM11 OEM-Aftermarket interface. So I disconnect the 12v accessory (switch) line and connect it to 12V constant and the head unit powers on. For those who don't know, the 12v accessory switch line does not come from the factory harness, it comes from the GM11 interface. So I check voltage across the 12v switch line, and no matter what position the key is in, including out of the ignition, it read about 1.3v.

Obviously I can't leave both the 12v switch and 12v battery connected to constant, the stereo does not shut off. I also have the same GM11 interface in my 2004 Sunfire and it works fine with my aftermarket head unit in that car. So I tried swapping the GM11 interfaces back and forth between cars, and they both worked in my car, and neither would provide the 12v switch on the Grand Am.

Google has failed me. But led me here for hopefully some insight.

[Blackhawk]

Use the sunroof fuse or some other 12V switched source. Get a tap-a-fuse for it, don't rig it. Use your vm to check for a switched source.

[grizzlyaddams]

I thought of that, but there is no sunroof (the model is pretty basic, power locks ac abs are the only real features) and I checked the cig lighters and they are 12v constant. Looked at the fuse box and it shows nothing else i can use. I also checked the factory stereo harness for a 12v switched source (instead of taking the lead from the GM11) and there isn't one.

[car audio dave]

i think ive used the fuse for the wipers. stupid GM.

[Blackhawk]

You should have a location for the sunroof fuse, and it should be getting power to it. Members have used this to rewire their foglights for full control even if they don't have a sunroof, so I don't see why you couldn't use it. Anything switched, sunroof, wipers, etc.

[Mr03SC/T]

faulty gm11

[grizzlyaddams]

faulty gm11

This was my first assumption, but like I said, 2 different GM11 units work in my 2004 Sunfire, neither work in the Grand Am.

[grizzlyaddams]

You should have a location for the sunroof fuse, and it should be getting power to it. Members have used this to rewire their foglights for full control even if they don't have a sunroof, so I don't see why you couldn't use it. Anything switched, sunroof, wipers, etc.

This sounds good. But it's a moderately cheap stereo (Pioneer DEH-P6400M) that I bought for my girlfriends other car a few years ago. The factory unit has CD so I may not bother. Though she does like the MP3 CDs, she isn't even planning on keeping the car.

[iceman]

So, the GM11 is not receiving class 2 serial data in the grand am... but the stock radio works fine?? That's weird.

Not worth digging too deep, I'd run something to an acc fuse as well.