Condition	Retail	Price	Qty
Very Good	$0.00	$19.00	- +

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.

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Covers medium duty Chevrolet and GMC conventional truck models C6, C60, & C6000 with GM 4-53 diesel engine. To verify that this is the correct diagram for your truck, you can check your VIN code. The 4th digit should be a D for the medium duty conventional cab. The 5th digit should be D to indicate the 4-53T GMC diesel engine. The 6th digit should be a 9 for the 1979 model year.

1979 Chevrolet 40-60 Medium Duty

1979 GMC Series 4500-6500

1979 Chevrolet 40-60 Medium Duty 1979 GMC Series 4500-6500