I have a 2007 Cobalt SS w/ pioneer but w/o onstar, installing a Pioneer AVIC X940BT using PAC C2R-GM11 interface to make it an easy install and the AXXESS ASWC for Steering Wheel control retention. This should be an easy install and the wiring was self-explanatory, including hooking up the blue and white amp/antenna turn on wires but I get no sound from the Headunit. I get the door chimes and the blinkers though like I am supposed to. Any ideas? head Unit boots up no problem, but no sound....
Back story, I had the X920BT installed before with an older PAC adapter I had gotten from a friend who traded their HHR. It worked great until one day about a year later, no sound. I called up Best Buy who said the old PAC adapter must have gone out. No big deal, with a Baby on the way we were trading the car to my father-in-law for a brand new Optima SX and he was going to track the car. So i never replaced the adapter and took out the X920BT and sold it. No with gas prices my father-in-law abandoned the project after ordering parts and is going to save gas by driving the Cobalt. He bought the above items and I went to install as before and no sound.

 

something is going wrong with the remote turn on for the amp. you may have to bypass the pac blue white remote turn on and go directly from the pioneer blue/white to the pink wire in the stock cobalt harness (which should be ur remote turn on, please test)

 

^^ He's probably right. I had the same issue. I used a different adapter, but the amp wasn't turning on. Ran a wire to a fuse tap, solved.

 

Move wire 4b to 6b

 

Had to figure someone would be able to offer me an option that didn't include trying to access the factory amplifier. Thanks guys, I will try this out tomorrow evening and update you.
Question, why do you think the sound went out before though?

 

you dont have to access the factory amp u can do it from the radio end. in fact i wouldnt recommend trying to get it at the amp end

 

Guess I should of clarified. I didn't access the amp. Ran a wire from the pink to a fuse. So the amp would turn on. Just like EmperorJJ1 said.

 

Haha, no I really was thanking you all for the suggestions. I am planning on trying to work on the car tonight or tomorrow. Would be nice to have it all done by Sunday. They really made these cars easy to hide/run wires for the two antennas for this unit with the Sirius.

 

Well I gave up when the stupid SWC wouldn't work either. instructions were no help from the manufacturer. Anyways, I took it to an audio shop not too far from me and he has the same issues. $350 later and all I get is it looks nice, no sound. he tapped the amp turn on from the pioneer to the pink wire before the harness and still nothing. I have to wait until Monday to get him to even consider bypassing the amp and running the speakers straight to the head unit. I asked him to check the amp for a fuse but he says there isn't a fuse on the factory amplifier. This is a total headache.

 

Fuse for the amp in on the BCM in the passengers kick panel. Its the yellow 20amp fuse (I think its the only yellow)
If youre installer didnt bother even looking at the fuse box for a stock fuse, Id suggest going to someone else with common sense

 

^^^^ this

 

The amp wire in the harness is in the wrong place, there is a how to on installing pioneer head unit. U have to move the one pin, I just soldered the pink wire on cars harness to the blue white wire

 

Well the fun continues with this car. We found the problem and after I sent links to the wiring diagrams I found on this site, he located the amp fuse, on the passenger side where I had been telling him it was located. It was blown, so he replaced it. That fuse promptly blew when turned on. So we are just going to bypass the darn thing and I have access to a cheap amp that's been collecting dust that we will run to the factory sub. Just ready to get this thing done, what a headache!
BTW, we did wire the blue and white straight to the pink before the harness, that was before we located the fuse that kept blowing. The good news is, because I was right, thanks to you all for your help with that, he is going to knock off $50 from the price.

 

Id check that you arent shorting it out with your power bypass you did. Cut that first and see if the fuse keeps blowing. It also wouldnt be hard to follow the amps power line to see if its shorting out. Its only a span of a few feet from the BCM. The 5-10 mins checking it could save you a few hundred dollars. A multi meter is your friend

 

Thanks acoutu, I should have taken your advice. But the Cobalt now has sound, no sub for now, but sound. I kept the factory amp, might play around with is, but for now the plan is just to use an extra amp I have access to and just hooking it up to the factory sub. I have to admit though, the sound is quite nice coming from the head unit, not bad at all. Actually wishing this car was still mine. That Pioneer X940BT boots fast, mush faster than the X920BT I had in there before.