[Loekee75]

GM radio wires
*Note that some wires may be the same color; they will be divided based on their function. For example, the dark green lead controlling the radio face dimming feature will be in a different area of the harness used primarily for radio functions; another dark green lead will be located in a separate small bundle of wires used as a speaker wire.
This list pertains to several 1988 – 1995 GM vehicles, specifically the 1992 Buick Park Avenue and Park Avenue Ultra...and not all models may apply.

Orange- Battery input, hot at all times; (radio memory)
Yellow- ACCY power, fuse #24 (radio power while switch to “run”, ACCY, or retained accessory power
Black- Ground lead
Dark green- Headlight/ parking light dimming (used to dim radio display when headlights are on)
Gray- Interior lights dimming (used to allow radio display to dim with interior light dimmer switch)
Pink- Power antenna and/ or Delco/Bose sound system.
Purple/ white- “Pulse width modulated illumination signal from radio. Controls VF display illumination of heater and a/c control assembly and passenger climate control assembly with headlight/ parking light switch at head or park. Voltage varies as dimmer control is rotated.”
Dark green- Dimmer output for standard a/c and heater controls (non-climate control system)

Speaker wire colors
*The colors are the same for both the standard 4 speaker system and the Concert Sound II sound system. Note that the Concert Sound II door midrange speaker and tweeter both share the same leads.

Tan- LH front (+) for standard system, LH midrange and tweeter (+) for Concert Sound II
Gray- LH front (-), for standard system, LH midrange and tweeter (-) for Concert Sound II
Light green- RH front (+) for standard system, RH midrange and tweeter (+) for Concert Sound II
Dark green- RH front (-) for standard system, RH midrange and tweeter (-) for Concert Sound II

Brown- LH rear (+) for both standard and Concert Sound II systems
Yellow- LH rear (-) for both standard and Concert Sound II systems

Dark blue- RH rear (+) for both standard and Concert Sound II systems
Light blue- RH rear (-) for both standard and Concert Sound II systems

Hope this helps someone out. I'll get the Delco/ Bose system wires color coded some time in the near future!