GM Service Manual Online
For 1990-2009 cars only
Figure 1:

Early Production


Object Number: 1237742  Size: FS
Master Electrical Component List
Horns System Description and Operation
Fuse Block-I/P CIG, HORN, LT HDLP, CLSTR, EXT LP, FOG Fuses, and HDLP Circuit Breaker
Figure 2:

Late Production


Object Number: 1237743  Size: FS
Master Electrical Component List
Horns System Description and Operation
Fuse Block-I/P CIG, HORN, LT HDLP, CLSTR, EXT LP, FOG Fuses, and HDLP Circuit Breaker