Just wanted to post up some potentially useful information...
1987 GM speaker wire color codes:
Front Left POS = TAN
Front Left NEG = GRAY
Front Right POS = LT.GRN
Front Right NEG = DK. GRN
Rear Left POS = BRN
Rear Left NEG = YEL
Rear Right POS = DK. BLU
Rear Right NEG = LT. BLU
1987 GM speaker wire color codes:
Front Left POS = TAN
Front Left NEG = GRAY
Front Right POS = LT.GRN
Front Right NEG = DK. GRN
Rear Left POS = BRN
Rear Left NEG = YEL
Rear Right POS = DK. BLU
Rear Right NEG = LT. BLU
