I was wondering if anyone else had upgraded their stereos? When I try to transfer the wiring over from the new radio - I find that I need a wire for the 12V power and there doesn't seem to be one. I have theRed wirefrom the harness for the continuous power but this is for the clock and memory and stuff right? Where is the ignition wire? Anyone know what color it is in the harness? Does the factory stereo use the same wire for both?

The schematic I have says that the Red wire in slot B1 is for "battery" and is "hot all the time". TheOrange wire in A1 says "Class 2 Data" and goes to "Computer Data Lines System". What on earth is that for? Does anyone have any ideas?

 

Are you using an adapter plug you purchased ? If you are is this the schematic that you are referring to ?

What you are looking for is a swithced 12 volts to power the deck which may be a yellow wire in the vehicles wire harness.

If you're not sure which one this is you can find it by using a volt meter to find it ... don't use a test light. Just remember that newer GM vehicles will have 12 volts on this wire for a few minutes after the key is turned off or when a door is opened then it will turn off.

The vehicle wire that has a constant 12 volts is the memory and clock wire.

The " computer data line " can not and should not be hooked up to your aftermarket deck. The factory decks will have speed regulated volume control which is read buy the speed sensor on the vehicle by the factory stereo. As speed increases the stereo's volume will increase and as you slow down the volume will decrease.

 

You didn't say what year your Express is... but anyway all newer GM cars need this adapter

http://www.crutchfield.com/S-hDJe04q...sp?i=120GMRC01

Good luck

 

I have a similar issue. I had a stereo installed, and it stopped working all of a sudden. I am no longer getting power. I checked the usual suspects and I have power at the fuse box. I changed fuses, just in case. However still no power on the yellow wire. Constant power is fine, but since I have an AMP, I don't want to leave that running all night and wear down the battery.

Any ideas/suggestions?

Thanks,

Carlos