Here are the best places to look:
* Ford Shop Manual (FSM): This is the definitive source. A factory service manual for your specific year and engine (e.g., 302, 351, 390, 400, 460 etc.) will have detailed wiring diagrams. You can often find these online through eBay, Amazon, or specialized automotive manual websites.
* Haynes or Chilton Repair Manual: These are less expensive alternatives to the FSM, but the wiring diagrams may be less detailed. Make sure you get one for the correct year and engine.
* Online Automotive Parts Websites: Some parts websites (like AutoZone, Advance Auto Parts) offer free online diagrams, but access may be limited or require registration. They usually categorize by year, make, model, and engine. You might find a partial diagram, but not as comprehensive as a shop manual.
* Online Forums: Forums dedicated to classic Ford trucks (like FTE - Ford Truck Enthusiasts) are excellent resources. Experienced members may have scanned diagrams or can offer advice on tracing the wires yourself if you have the truck.
Important Considerations:
* Engine Size: The wiring will be different depending on whether you have a 6-cylinder or a V8 engine. Even within V8s (e.g., 302 vs. 351), the wiring might vary slightly. You MUST know your engine size.
* Specific Distributor: While the overall ignition system wiring is important, there might be subtle variations in the distributor's internal wiring depending on the specific part number. The FSM is your best bet to account for such variations.
Once you have a diagram, remember that colors may have faded over time, and wires may have been spliced or replaced. Careful inspection is always necessary.
