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.
1979 Truck Wiring Diagrams MD17851
This item is original.
11.00 x 8.50 x 0.10 inches
Covers GMC Astro and Chevrolet Titan, also known as D9 with Detroit Diesel except 8V-92. To verify that this is the correct diagram for your truck, you can check your VIN code. The 4th digit should be either a K or an L for heavy duty aluminum tilt cab, the 5th digit should be a D, H, I, J, or V to indicate the Detroit Diesel engine, and the 6th digit should be a 9 for 1979.
1979 Chevrolet Titan 90
1979 GMC Astro 95
1979 Chevrolet Titan 90 1979 GMC Astro 95