OK guys, my wifes '95 850 Turbo has had a intermitent cruise control problem. It would work most of the time, but shut off at random, reset and good to go.
Someties it wouldnt set at all.
Now it just wont work. Where is the cruise control module under the hood? Is it vacum ran? Is maybe the cruise computer bad? Maybe the brake pedal switch?
Any ideas?

 

See text attached sorry can't upload a PDF

 

Thank you, no problem on the PDF. I will check the throotle cable and then the vacum line at the brake pedal.
I was messing with the EGR and PCV the day before it died completly. The EGR valve is bad so i was looking to see if I could remove and clean it. I may have messd with one of the throttle cables I suppose.

 

Spike,

The vacuum that operates this is not at the throttle cables, it moves the actual throttle pedal itself. In addition it is a vaccum pump not engine vacuum (Would work backwards when you got boost). My guess is it is electrical. The intermittant problems you mentioned are most likely not vacuum or mechanical. If these modules are anything like those in 94'+ Volkswagens then it is not surprising if the module is bad.

 

The vacuum pump is under the battery. Check hoses from it to inside. also check the vacuum sensor by the brake pedal and make sure it is adjusted properly.

 

Thanks guys, I will check those tommorrow. This car is WAY more complicated than my Rover. I hope that it is just a simple vacum leak.

 

I cannot find a vacum leak. SO you guys think it might be the cruise control unit?

 

I haven't see any go bad yet.
Did you check the switch under the dash yet for the vacuum?

 

I tried but I cannot see/find it. I used a flashlight of course but am I not seeing it. On the back of the brake pedal right?
Can you describe it to me?

 

It should be infront of the pedal but I believe above the brake light switch. Look for a switch that has a vacuum line going to it.
My Yellow one does the same thing but evertime I check things out all seems fine. But also sometimes I need to pull back on the brake pedal for it to work.

 

OK, thank you. I must have missed it, its pretty tight under there. I will look again today and also try pulling the brake pedal out.
I used to have Chevy that the brake lights would stay on until you pulled the pedal back out with your foot.

 

So after throwing my back out crawling under the dash I still cannot see a damn thig. I see the brake pedal, the bar that goes through the firewall into the engine bay to the master cylinder, I see part of the brake light switch, but nothing else.
The bottom of the dash covers everything. It is very well built and neatly pout together, I am pleased with that, but man, what a pain in the rump to try and fix.
We will have to take it in to get fixed once we have the money I guess.
Thanks for all the help guys.

 

The cruise switch should be just above the brake light switch I believe. Did you remove the lower dash panel?

 

No I didnt remove the lower dash panel, I did not realize that it could come off.
It will have to wait until my back feels better now. Its all I can do to leave the sofa. lol.

 

Sorry to hear about your back I feel your pain been there done that.

 

I really wrenched it a couple of weeks ago moving furniture in the house and it was feeling better, then I layed on the foot well flat on my back to look under the dash and when I went to get up I couldnt hardly move.
At least it is a long weekend and I can recover before Tuesday. lol. It sucks getting older.

 

Yes it does suck getting older.

 

Ok, removed the lower dash panel and found the cruise brake switch, the vacum hose looks good as far back as I can see. Still nothing. No cruise and it is getting very annoying.
I dont know where to look next.
Ideas?
Thanks again for all your help so far guys.

 

Do youanyone you can borrow a hand vacuum pump from?
Or you might be able to rent one from a local parts store.
This way you could 100% rule out a vacuum problem.
I used to have the diagram on how to remove the relay and jump with wires to activate the pump motor but I cannot find it or I would have posted it for you.

 

Where is the cruise pump? I think somebody said that it was under the battery, I will go back and re-read.
How do I test the cruise pump with a hand pump?