Cruise Control not working
Thread Starter
Instructor
Joined: Oct 2002
Posts: 218
Likes: 4
From: Durham NC
Cruise Control not working
The cruise control on my 85 does not work. At one point it failed to work and then later started back working. Now it is out of order seemingly for good. What do I ned to check before I begin replacing parts? I want to do some troubleshooting before I begin. Is the servo the only thing that goes bad or are there other things that I should check out first?
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Check the vacuum lines that feed the servo... they are prone to failure.
You don't mention it, but does the climate control work ok? A broken vacuum canister can most surely cause this problem.
You don't mention it, but does the climate control work ok? A broken vacuum canister can most surely cause this problem.
Le Mans Master
Joined: Jun 2002
Posts: 6,097
Likes: 0
From: High Plains Drifter Fayetteville, AR
Originally Posted by bogus
Check the vacuum lines that feed the servo... they are prone to failure.
You don't mention it, but does the climate control work ok? A broken vacuum canister can most surely cause this problem.
You don't mention it, but does the climate control work ok? A broken vacuum canister can most surely cause this problem.
Vacuum line runs from the canister along the driver side fender in the wire harness to just behind the alternator where it "t"s off to the engine. Follow the harness along the fender to the cruis control.
Thread Starter
Instructor
Joined: Oct 2002
Posts: 218
Likes: 4
From: Durham NC
I have vacuum on the line coming from the cannister. I assume that the amount of vacuumk is sufficient. However, there is a vacum line that goes to somewhere else under the car. Should there be suction there also? And, yes, the heater/AC controls seem to work as they should.
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Melting Slicks
Joined: Feb 2002
Posts: 2,699
Likes: 2
From: The Black Hole LA
Could very well be the switch in the steering column. I have seen quite a few of these go out on older/higher mileage GM vehicles. The trucks seem espesially bad about it for some reason. I've got a friend that has had to replace his in a truck twice in the past 13 years he has had it.
Sorry though I forget the procedure for checking this.
Sorry though I forget the procedure for checking this.
Drifting
Joined: Nov 2002
Posts: 1,593
Likes: 0
From: Mobile AL
St. Jude Donor '05
Originally Posted by dans86
Check the position of your sensors down by your pedals, they might need to be repositioned.
Thread Starter
Instructor
Joined: Oct 2002
Posts: 218
Likes: 4
From: Durham NC
Thanks for all the replies. This forum is the greatest. I am going to chek out the vacuum switch near the break pedal tomorrow. The vacuum line that I did not know where it was going is the one going to the break pedal. I'll check the positioning of this tomorrow. Does this vacuum switch ever need replacing? I want to make sure that the problem is not the servo before I buy one. That thing is too expensive to buy if it is not needed. Again, thanks for all the great replies.
Burning Brakes
Joined: Apr 2000
Posts: 980
Likes: 2
From: Chandler AZ
Originally Posted by J H
I want to make sure that the problem is not the servo before I buy one. That thing is too expensive to buy if it is not needed. Again, thanks for all the great replies.
Drifting
Joined: Jan 2002
Posts: 1,261
Likes: 4
From: Middle River MD
When mine stopped working it was the switch connected to the brake pedal that had come loose. Got it back together and it started working properly. However, it has since stopped working again and I haven't gotten under there to mess with it again 
Team Owner
Joined: Jan 2003
Posts: 20,290
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From: Summerland B.C. Canada
Melting Slicks
Joined: Jul 2003
Posts: 2,384
Likes: 124
From: Reno/Sparks Nevada
My CC went out some time back. Traced it back to the CC switch on the turn signal stock. This part is over $100 so a thorough test is necessary so you don't throw money at the car. The link that Agent86 posted looks like the hot ticket for troubleshooting the system. A vacumm leak to the servo or a leak in the line going to the brake vacumn switch will cause it not to work. Funny thing about the new switch I bought from the dealer, it was defective too right out of the box. I didn't realize this til after the warranty ended because I didn't install it til a couple of months after I bought it. What are the odds of that happening? Anyway, replaced it again and it works fine. Darn GM parts.
Art
Art
Thread Starter
Instructor
Joined: Oct 2002
Posts: 218
Likes: 4
From: Durham NC
Thanks a million for all the replies. I have checked everything out that was suggested and all seemed to work as specified. Therefore, I have ordered a servo from AutoZone. The cost was $59.99 plus the core charge of $20.00. I figure that at that price, I could take the chance at that being the problem. Eckler's wanted $299.00 for the servo. The price difference is great, but since this is not a critical engine part, I can take a chance at the much cheaper part being OK for a while. When I get it installed I'll post the results. Again, thanks for all the great replies.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Thread Starter
Instructor
Joined: Oct 2002
Posts: 218
Likes: 4
From: Durham NC
I have the Helms manual as well as the Haynes. Contrary to what many of you think, I like the Haynes better. But, that's just my feeligs. The Helms has the advantage as far as schematics, etc. are concerned, but the Haynes usually provides me with the best "how to" information.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Originally Posted by J H
I have the Helms manual as well as the Haynes. Contrary to what many of you think, I like the Haynes better. But, that's just my feeligs. The Helms has the advantage as far as schematics, etc. are concerned, but the Haynes usually provides me with the best "how to" information.
The earlier Helm manuals are no where near the quality of the later manuals. Night and day difference.