Original 1975 Chevrolet Dealer Electrical Wiring Diagram Service Manual Supplement. This wiring diagram manual covers the following models C-10,20,30: C-15,25,35; K-10,20,30; K-15,25,35; P-10,20,30; P-15,25,35' G-10,20,30; G-15,25,35; C-80; D-80. Refer to 1974 Truck Wiring Diagram Book for all 1975 model trucks NOT covered in this booklet (those built prior to March 1, 1975). These detailed Wiring Diagrams are what the Dealership used to diagnose and repair your Chevy. Very useful and rare since they were not offered to the public. ST-352-75