This is the original wiring diagram printed by GM for dealer mechanics. You can follow the wiring in your truck from bumper-to-bumper. It will help you to understand connector configurations, and locate & identify circuits, relays, and grounds. Although the schematic is in black and white, the color of each wire is noted. You will not find this diagram in your shop manual. The schematic measures 8.5" x 11" when folded up, and opens up to 11" by 38". The diagram pictured is an example of this type when folded, but is not the actual diagram for your vehicle. Buy now for the best electrical repair info - the factory wiring diagram.
"Cab, Engine and Chassis Wiring -- HI/JI/MH/MI- 9500 MD-3749"
This item is original.
8.50 x 11.00 x 0.10 inches
This book covers 1970 GMC 9500 Conventional models also known as HI or JI, equipped with the 6-71 diesel engine. See my other items for other engines. To verify that this is the correct diagram for your truck, you can check your VIN code. The 1st digit should be an H or a J for the heavy duty steel conventional cab, the 2nd digit should be an I for the 6-71 Detroit Diesel engine.
1970 Detroit Diesel Engine 71 Inline
1970 GMC Series 7500-9500
1970 Detroit Diesel Engine 71 Inline 1970 GMC Series 7500-9500