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

Left Rear of the Engine Compartment (Heavy Duty)


Object Number: 886073  Size: MF
(1)C109
(2)Brake Fluid Level Switch Connector
Figure 2:

Power Brake (PB) Booster Fluid Alarm Switches Harness Routing (UJ1)


Object Number: 883605  Size: MF
(1)Power Brake (PB) Booster Fluid Pressure Alarm Switch Connector
(2)C141
(3)Power Brake (PB) Booster Fluid Flow Alarm Switch - C1, C2
Figure 3:

I/P Harness Routing - Left Side of the Passenger Compartment


Object Number: 883611  Size: MF
(1)Park Brake Switch
(2)Park Brake Switch Connector
(3)C220
(4)C311
(5)C318
Figure 4:

Chassis Harness Routing (Passenger/Cargo)


Object Number: 1371219  Size: LF
(1)Fuse Block Underhood - C3
(2)Fuse Block Underhood - C7
(3)Fuse Block Underhood - C8 (UY7)
(4)Wheel Speed Sensor (WSS) Connector - RF
(5)Brake Pressure Differential Switch Connector (Light Duty)
(6)Evaporative Emission (EVAP) Canister Vent Solenoid Connector (Gas)
(7)S301
(8)Electronic Brake Control Module (EBCM) Connector (JL4)/Electronic Brake Control Module (EBCM) - C2 (w/o JL4)
(9)Electronic Brake Control Module (EBCM) - C1 (w/o JL4)
(10)Trailer Right Stop/Turn Relay (UY7)
(11)Trailer Left Stop/Turn Relay (UY7)
(12)S315 (JL4)
(13)G300
(14)Wheel Speed Sensor (WSS) Connector - LF
(15)C101