1973 Pontiac GTO 11" X 17" Color Wiring Diagram Diagram covers the complete basic car including: interior and exterior lights, engine & engine compartment, firewall, under dash, instrumentation, etc. All wire colors (including tracers) and component information is from the original factory service manuals. This means the wire colors on the diagram are the same as what is in your car. All text is crystal clear and easy to read, and all colors are easy to distinguish. The diagram is laminated in rigid plastic for years of use. Large 11" X 17" Tabloid Size.