2002 Montana. Can't get the radio to turn on (black screen). Yes the red security lamp is on and cd will eject but no readouts or power. Only 1 wire that powers the unit is on full time. No other wires have power, when I turn on the ignition. Fuse under hood is good and is getting power. (I used a test light). I know I should have a second power supply but I don't know which wire to splice into. Could it come from the Onstar overhead? This van is new to me and was beat to hell but she runs and rides nice. Any advice is welcome. ~needstunes~

PS. I don't have a the keyless remote. I only have the key.

i only see the orange in the drawing as being power. two black/whites are ground. there is a power on signal on pink but it goes to the steering wheel controls. not sure how this works but by its name maybe you have to have something there to turn the radio on. there is the chance the radio is just bad. they do have security so if its not the original radio it has to be programed i dont know what that looks like either if your light is on maybe thats what that means. they need to have the vin programed in them to work or the older type has codes you have to type in to unlock it.

https://www.gmforum.com/2000-2005-90...t-turn-300431/

I think the airbag was deployed. I did read that the pink wire is ign on. It was probably severed inside the wheel.
I don't have a pink wire but I have 2 orange wires. One is always hot and the other is dead. If I knew for sure about the ign hot....I can tap in a new wire to it. Yes, I found instructions on how to unlock it, but I need to get the screen active first.

something isnt right, i looked in two spots for diagrams and they only show the one always hot for your car and the pink seems more likely an output to the video and steering. the video, and radio are both connected to the class 2 serial bus so that could be how they turn on. if thats the case could be the newer radio and needs programmed by the dealer.

I agree that this is odd. I just wish I could find out the color code schematic for a 2002 radio. That'll help me if I wire in a new radio. I can't justify a $100 for the proper adapter. I've only got $900 in this van.

PS. Thank you for all your help. Seriously.

Did you check all the fuses? I seem to remember having a similar problem and it was a aux fuse not radio giving me the issue. When ever I have electrical issues I usually run the test light across both sides of all fuses with the key on.

you can get the cheap ebay non onstar adapter or wire it direct wire to wire. you just lose your chime, onstar, and the things that are adjustable through the radio you wont be able to access, not like you could before. for the switched wire just find a fuse on the retained accessory power circuit and go to the parts store and pick up some fuse taps. and you can add the switched wire that way.

Car Radio Battery Constant 12v+ Wire: Orange
Car Radio Accessory Switched 12v+ Wire: The radio harness does not provide a switched power source. Run a wire to the fusebox for switched power.
Car Radio Ground Wire: Black/White
Car Radio Illumination Wire: N/A
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: N/A
Car Audio Front Speakers Location: N/A
Left Front Speaker Positive Wire (+): Tan
Left Front Speaker Negative Wire (-): Gray
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Dark Green
Car Audio Rear Speakers Size: N/A
Car Audio Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): Brown
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Dark Blue
Right Rear Speaker Negative Wire (-): Light Blue