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

L18


Object Number: 1842288  Size: FS
Master Electrical Component List
Cruise Control Description and Operation (8.1L)
Control Module References
Cruise Control Schematics - LG4/LLY
AXL/4WD, BRK, HYD/AIR BRK, and HTR/AC Fuses/Circuit Breakers
Stop Lamp Switch
AXL/4WD, BRK, HYD/AIR BRK, and HTR/AC Fuses/Circuit Breakers
ENG-1 and ENG-4 Fuses - L18/LLY
Figure 2:

LG4 and LLY


Object Number: 1842292  Size: FS
Master Electrical Component List
Cruise Control Description and Operation (6.6L and 7.8L)
Control Module References
Cruise Control Schematics - LG5
Cruise Control Schematics - L18
AXL/4WD, BRK, HYD/AIR BRK, and HTR/AC Fuses/Circuit Breakers
Stop Lamp Switch
AXL/4WD, BRK, HYD/AIR BRK, and HTR/AC Fuses/Circuit Breakers
ENG-1 and ENG-4 Fuses - LG4/LG5
Figure 3:

LG5


Object Number: 1842299  Size: FS
Master Electrical Component List
Cruise Control Description and Operation (6.6L and 7.8L)
Control Module References
Cruise Control Schematics - LG4/LLY
AXL/4WD, BRK, HYD/AIR BRK, and HTR/AC Fuses/Circuit Breakers
AXL/4WD, BRK, HYD/AIR BRK, and HTR/AC Fuses/Circuit Breakers