Very Good
$29.00Add to Cart


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.


Be the first to submit a review on this product!
Review and Rate this Item


Exact Title: "Cab, Engine and Chassis Wiring - HM/JM-75013; 80013 MD-7737"
Page Count: 1
Wiring Diagrams?: Included
Authenticity: This item is original.
Dimensions: 11.00 x 8.50 x 0.10
OEM Part Number: MD7737-74

Model-Years Application

This book covers 1974 GMC and Chevy 70 80 7500 8000 Conventional models also known as HM or JM, equipped with a V6 gasoline engine. See my other items for the diesel diagrams. To verify that this is the correct diagram for your truck, you can check your VIN code. The 2nd digit digit should be an H or a J for the heavy duty steel conventional cab, the 3rd digit should be an M for the V6 gas engine and the 6th digit should be a 4 for the 1974 model year
1974 Chevrolet 70-90 Series Heavy Duty
1974 GMC Series 7500-9500


Pin It

Email A Friend

Send your friend a link to this product.