Anybody got any diagnostic flow charts wiring diagrams or theory & operation info on these early cruise control systems mine is not working and is the only thing on my truck(83 f350 diesel) that dont work so its really buggin me! I have checked all of the obvious things fuses vacuum lines and no wires or connectors are damaged so with no additional info im stuck. I know alot of you folks on here worked for ford when these trucks were new enough to take to a dealership so im hoping someone knows something about these things.AS usual i appreciate all your info,Thanks

 

Look down through this forum at all the posts that are around a week old. There was a pretty large thread on just this subject.

 

Does your horn work?
I have a diagram from an '86. Link in my signature.

 

If I knew where Douglasville was I might be able to help you. I have a Rotunda cruise control tester.

 

Cruise control is a GM term. Speed control is a Ford term. Use the Ford term in your search also. Could be the servo. Make sure you have a good vacuum source going to it. Also sometimes the gears get all cattywompus inside the servo. You may need to take it apart inspect it and clean/grease everything back up.