that's not troubleshooting, that's replacing random parts, the only similarities are it's a mustang part for cruise control.Wow lot of great info here, my cruise control broke over a year ago and I couldnt find any info on this subject, thanks loads.
In regards to the amplifier I pulled one from a junkyard a while back and its black but cant remember the year i got it from but i think it at least was an 86(mines a 90LX and has a yellow amplifier) The one i pulled from scrap dosent have an id sticker(i can see where it used to be) and no part # that i can find in the molding. Do we know if there is any difference between the amplifiers? Or is it at least safe to hook it up and try? I want to start there. it seems like changing the amplifier and plugging the vac line thats at the pedal assembly seem to be the easiest first steps in troubleshooting the cc.
Did you ever test that Rotunda?Jack the rear off the ground and you can test it “driving” like that. Not the safest but it can be done easily.
The Ford manual actually tells you to disconnect the cable from the throttle body just in case it does go WOT during testing.