Handbook 652 Body Electrical Diagnosis Overall Wiring The Overall Wiring Diagram presents all of the electrical wiring and components in the vehicle in a single diagram spanning more than 60 pages . This is the format that was common in earlier days. Diagram To find individual circuits on such a massive diagram, coordinates are printed across the top of the diagram, and a system circuit index lists page number and coordinate where each circuit begins. The System Index is in the “ How to Use the Overall EWD ” part of the Overall Wiring Diagram section. The Overall Wiring Diagram is much more difficult to use than system circuit diagrams and their supporting sections of the EWD.
For exceptionally difficult troubleshooting problems, however, the Overall EWD may reveal relationships between circuits that aren ’ t clear when looking at individual system circuit diagrams. It can also be used to double-check potential typographical errors in other diagrams. Technical Training 91