Weird cruise control problem!?!?

[TireFryer]

Was driving home today, set my cruise, the light came on, and then nothing happened. The cruise didn’t come on even though the dash light was on. Tried a reset, tried accelerating, tried messing with the brake pedal… any idea why the light would come on on the dash saying it was working, but the cruise doesn’t actually work? The cables are connected, if I press the cruise diaphragm it revs the engine, the vacuum lines are good… It worked this morning. Now it doesn’t.

 

[Turbo6inKY]

Module failure. They're all old and the capacitors are giving up.

You might be able to pull the module and take it a TV repair shop and see if they can re-cap it for you.

 

[1986 Buick GX1]

I suspect a leaky diaphragm. Try applying vacuum to the servo diaphragm to see if it pulls the cable and opens the throttle.

 

[TireFryer]

Just the main vac like that runs to the diaphragm? The car still pulls 18 “vacuum units” or whatever the measurement is on the scanmaster lol.

 

[XracerX]

Try pushing in the activating button on the cruise lever stalk and rotating it while its pushed in. See if that works. I had to do that one or two times since 1987 to get it to work.