Stereo Wiring Diagrams Stereo Wiring Diagrams. Welcome to Stereowiringdiagram, one of the leading websites for car stereo color coded diagrams carry common radio/stereo wiring information for the majority of vehicles made by common automakers.Chevorlet · Request Stereo Diagrams · Ford · Toyota · Hyundai · Nissan How to Identify Aftermarket Car Stereo Wire Colors If you have the pigtail that came with your aftermarket head unit, and it uses the standard colors, then the wires will have the following purposes and colors: Power Wires Constant 12V / Memory Keep Alive — yellow. Accessory — red. Dimmer/illumination — orange w/white stripe. Ground Wires Ground — black.