seaeagle

My cruise control on a 1990 C4, RHD, is behaving erratically. Sometimes won't work, then starts to work after 1/2 hour. Other times, you set, with no effect, and then change gears, reduce speed, and it then automatically goes back to the re set speed that did not originally work.

Anyone had a similar problem, and if so is it easily fixed? Or is it time to replace the cruise control system (which I am dreading thinking about the cost- and indeed the need!). Cruise control is good on freeways with speed cameras, police about etc. But not really necessary. So its a nice to have, but not essential.Ie would you sped a lot of money fixing it?

David P

Hi

I had a similar problem a couple of years ago. It turned out to be the switch under the brake pedal whihc deactivates the cruise control when pressed. Have a look at the dealer manual on page 46 -4 on how to adjust it.

David P

yellowducman

When I bought my car the cruise control didin't work and it was the switch on the clutch pedal was out of adjusment. Free and easy fix.

David P

Ah, I think you are right, it might have been the one on the clutch pedal...

mshobe

Good to know — I'll have to look for that switch because my cruise control engages quite erratically (but once engaged, Holds Steady.) I suspect the clutch pedal switch since that sounds like it needs to be flipped to the right setting to enable cruise. Do you have to just move some carpet outta the way to access it?

jgrosjean

Mine worked until two days ago. Would not engage and then suddenly decided to accelerate I didn't expect it to. I was in a line of traffic, so it required a fast tap on the brake. Will check the clutch switch first.

elbeee964

I'll piggy back on the clutch pedal microswitch... though my microswitch was perfectly in adjustment.

Turned out to be a side symptom of a bad slave cylinder -- that the pedal's return spring didn't have enough umph to fully return a depressed pedal. So, the pedal 'hangs' just shy of full returned position.
Doesn't hurt anything except that cruise microswitch reads this as a 'cruise-disengage' position of the pedal.
So, it won't let you engage the cruise.
Pull the clutch pedal out from behind with the back of your foot to fully released position, and - voila! - a perfectly functioning cruise.

Replaced the slave (and slave hose) and allll sorts of things begin working as they should.

I really, really dislike that slave cylinder and the ways it fails...
-Lonnie