GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 TopKick C-Series (Crew) C4/C5 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 HVAC Schematics
Figure 1:

Heat Only
Object Number: 799888 Size: FS
Master Electrical Component List
Air Delivery Description and Operation
Blower Controls (C60)
B+ Bus Bar
Ignition Switch - RUN and ACC/RUN Bus Bars
AXLE/4WD, BRAKE, CHASSIS, and HTR/AC Fuses/Circuit Breakers
Interior Dimming Lamps System
G103 - 1 of 2, G105, and G106
G103 - 1 of 2, G105, and G106
G103 - 1 of 2, G105, and G106
G200, G202, and G203 - 1 of 4
Figure 2:

Blower Controls (C60)
Object Number: 1464306 Size: FS
Master Electrical Component List
Air Delivery Description and Operation
A/C Compressor Controls (C60)
Heat Only
B+ Bus Bar
Ignition Switch - RUN and ACC/RUN Bus Bars
AXLE/4WD, BRAKE, CHASSIS, and HTR/AC Fuses/Circuit Breakers
Interior Dimming Lamps System
A/C Compressor Controls (C60)
G103 - 1 of 2, G105, and G106
G103 - 1 of 2, G105, and G106
G103 - 1 of 2, G105, and G106
G200, G202, and G203 - 1 of 4
Figure 3:

A/C Compressor Controls (C60)
Object Number: 1464309 Size: FS
Master Electrical Component List
Air Temperature Description and Operation
Auxiliary Controls (C36)
Blower Controls (C60)
Ignition Switch - RUN and ACC/RUN Bus Bars
A/C COMP, HTD FUEL, PCM-B, and RR DEFOG Fuses
AXLE/4WD, BRAKE, CHASSIS, and HTR/AC Fuses/Circuit Breakers
Blower Controls (C60)
G100 (L18)
G100 (LB7)
G100 (LG4)
G100 (LG5)
Figure 4:

Auxiliary Controls (C36)
Object Number: 799893 Size: FS
Master Electrical Component List
Air Temperature Description and Operation
A/C Compressor Controls (C60)
Ignition Switch - RUN and ACC/RUN Bus Bars
BATT/HAZ, HAZARD, PWR ACCY, STOP, and TRLR TRN/HAZ Fuses/Circuit Breakers
AXLE/4WD, BRAKE, CHASSIS, and HTR/AC Fuses/Circuit Breakers
BATT/HAZ, HAZARD, PWR ACCY, STOP, and TRLR TRN/HAZ Fuses/Circuit Breakers
G102 - 2 of 2