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

L18/LB7/LG4/LLY


Object Number: 1464551  Size: FS
Master Electrical Component List
Cruise Control Description and Operation (6.6L and 7.8L)
Ignition Switch - RUN and ACC/RUN Bus Bars
AXLE/4WD, BRAKE, CHASSIS, and HTR/AC Fuses/Circuit Breakers
ENG 1 and ENG 4 Fuses (L18/LB7)
Figure 2:

LG5


Object Number: 795102  Size: FS
Master Electrical Component List
Cruise Control Description and Operation (8.1L)
Ignition Switch - RUN and ACC/RUN Bus Bars
AXLE/4WD, BRAKE, CHASSIS, and HTR/AC Fuses/Circuit Breakers
Device Controls - Switches