A wiring diagram is primarily used for troubleshooting electrical problems within a vehicle's electrical system. Our wiring diagrams show wire color, wire gauge, circuit number, wire position with in a connector, and graphics of to-and-from locations. Our 1963 Chassis Wiring Harness Diagram is fully-laminated (both sides). So, while working on your vehicle, any grease/oil/dirt smudges can easily be wiped clean. Our wiring diagrams graphically display all the wiring for a base model car (without factory options). Our diagrams are reproductions of those used by General Motors' mechanics, except they are displayed on one large page (not across multiple small pages). Reprinted with permission from General Motors Corporation.