My buddy gave his old Pioneer car stereo. None of the wires are labeled. I've done some searches with no luck. Are there websites that post schematics, or color codes for electronics?

 

If you are asking about the stock head unit, the factory wiring drawings for both the tC and xA/xB appear in this topic:
https://www.scionlife.com/forums/viewtopic.php?t=57619

There's not quite enough detail in your question to to go much further...

 

Thanks for the info, but the install is going to be on my 93' Isuzu pickup. I was thinking of getting an adapter from Best Buy or somewhere. The stereo is a Pioneer DEH-P2000 model.

 

that Pioneer uses standard EIA color code which is:
Yellow-battery or memory wire, hook up to a constant 12v
Red- accessory wire, hook up to a switched 12v wire
Black- ground
Blue(maybe blue/white)- power antenna/amp turn-on wire
white-left front speaker (+)
white/black-left front speaker (-)
gray-right front speaker (+)
gray/black-right front speaker (-)
green-left rear speaker (+)
green/black-left rear speaker (-)
purple-right rear speaker (+)
perple/black-right rear speaker (-)

 

Thanks, violent_b

 

i just took out my deck a few minutes ago... there is no black wire. i have a 2006 tC... i just need to find out which colors are for the SPEAKERS. Please help.

EDIT: NVM I FOUND IT, THANKS ANYWAY. :D

 

actually... i found the wrong schematic... lol... so i still need help... sorry.