GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2007 🢒 TopKick C-Series (Conventional) C6/C7/C8 🢒 Power and Signal Distribution 🢒 Wiring Systems and Power Management 🢒 Upfitter Provision Schematics
Figure 1:

C103 - Upfitter Auxiliary Wiring Connector
Object Number: 1842189 Size: FS
Master Electrical Component List
Control Module References
PTO Connectors
PNP Switch and Transmission Optional Connector (LG4/LG5)
C 102 - Upfitter TRANS OPT Connector and Internal Mode Switch
Solenoids
C305 (Upfitter Lighting Connector)
Figure 2:

Power Take-Off Connectors
Object Number: 1849541 Size: FS
Master Electrical Component List
Control Module References
C103 - Upfitter Auxiliary Wiring Connector
w/o LG5 2 of 2
w/o LG5 1 of 2
w/LG5