Useful GM Wiring Color Codes

[Russ T.]

I stumbled upon some useful information while reviewing shop notes concerning GM wiring codes for older cars. Yes Virginia, GM may have actually used some logic for this application. This information was obtained from the April '94 issue of Corvette Fever magazine and may be helpful during electrical trouble-shooting.

Red = 12+ volt delivery
Black = Ground
Brown = For turning something on & off
Blue = For powering lights & transmitting electrical signals
Purple = For momentary connectors (e. g., starter)
Yellow = Signal-type info (e.g., door switches)
Green = For info associated with contact points (e.g. coils)
White = For a pulse, as well as being common in ignition signal pulsing

[William C.]

Re: Useful GM Wiring Color Codes

Actually, the codes are standard SAE codes. The SAE Standards comittee, essentially adopted the GM-Packard Electric division engineering standards to apply to the industry in the early 60's.