Cruise Control Problems

[RS23VOA]

Hey guys.
1970 Challenger
Trying to figure out why my cruise control isn’t working. The solenoid clicks when I turn it on and clicks when I hit the “set” button but it won’t hold. I have a new diaphragm and have good vacuum. I’ve run a ground wire from the - on the battery to the CC unit and it didn’t help Anyone had this experience they can help shed some light on ?

 

[sixpactogo]

If the cruise kicks in but slowly loses speed, the diaphragm is losing vacuum somewhere. If it won't start at all, it could be any number of reasons. Even a brake light out or a bad connection.

 

[EV2RTSE]

New diaphragm for the servo? Would be interested in hearing more about that. Sorry no help on your problem but following along as my car is N88 equipped as well. Hopefully when the time comes I have a good working servo out of the ones I've accumulated over the years. So far I've done the click test on them too but actually using one on a running car is another matter.

 

[Challenger RTA]

I seen this a few days ago. I forgot to look if there is a filter under the cover. Bad or blocked. That will keep it from working.