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

Mobile Radio Power (9L4)


Object Number: 1916648  Size: FS
Master Electrical Component List
Control Module References
Roof Beacon Wiring (TRW)
Figure 2:

Roof Beacon Wiring (TRW)


Object Number: 1916654  Size: FS
Master Electrical Component List
Control Module References
Emergency Vehicle Wiring (5Y0)
Mobile Radio Power (9L4)
Figure 3:

Emergency Vehicle Wiring (5Y0)


Object Number: 1916667  Size: FS
Master Electrical Component List
Control Module References
Wrecker Wiring (5X7)
Roof Beacon Wiring (TRW)
Figure 4:

Wrecker Wiring (5X7)


Object Number: 1916683  Size: FS
Master Electrical Component List
Control Module References
Emergency Vehicle Wiring (5Y0)