Cruise Control Not functional
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Team Owner
Joined: Feb 2006
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From: sw Ohio
Cruise Control Not functional
Sometime last year my cruise control started going on the fritz, it would work intermittently and then it just stopped altogether. I went out and checked the rubber hoses, one had a crack in it on the end, so I trimmed it up. Still no luck. I noticed that there is no light on the dash anymore when I try to turn it on so is it an electrical problem?
Le Mans Master
Joined: Jan 2003
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From: Santa Maria CA
Thread Starter
Team Owner
Joined: Feb 2006
Posts: 24,460
Likes: 7
From: sw Ohio
Heel & Toe
Joined: Feb 2008
Posts: 18
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From: Sweet Home OR
I was able to get my 1986 cruise control working again. Through info found here, on the above link and other places, I had determined that the vacuum motor worked as it should, the vacuum dump switch at the brake pedal worked as it should but still no joy.
One big clue was that I didn't hear or feel the noticeable click at the vacuum motor with the ignition on and turning on the switch at the stalk. I had determined that the green wire in the harness from the stalk switch to the connector under the dash was open somewhere between the switch and the plug. I made a new harness(I hate to buy if I don't have to) and after re-installing everything, I now had the click when doing the "switch on" test. Took it out for a test drive and still no joy.
I then finally found a post on thirdgen.org that showed me what connects to what from the stalk switch to the plug. Further testing showed that the set switch was permanently engaged. I took the switch apart and found that the brass connector on the end of the "Set" plunger had come off and was always making the "Set" connection since it couldn't retract. I reattached the brass piece to the plunger and on the test drive...yeehaa! I have a working cruise control.
I thought I should give back for all the help others have given, albeit in bits and pieces all over the net, by gathering all I had learned into one place and posting it here. To that end, I have drawn up three diagrams relating to the switch and harness, but haven't yet finished the rest.
Still, if you have done all the other tests on the vacuum motor, and Duh! verified the fuse is good, you might start suspecting the switch.
Here's a link to those diagrams: ecapmiill.home.comcast.net/cc.html
Hope you find it useful,
Jim
One big clue was that I didn't hear or feel the noticeable click at the vacuum motor with the ignition on and turning on the switch at the stalk. I had determined that the green wire in the harness from the stalk switch to the connector under the dash was open somewhere between the switch and the plug. I made a new harness(I hate to buy if I don't have to) and after re-installing everything, I now had the click when doing the "switch on" test. Took it out for a test drive and still no joy.
I then finally found a post on thirdgen.org that showed me what connects to what from the stalk switch to the plug. Further testing showed that the set switch was permanently engaged. I took the switch apart and found that the brass connector on the end of the "Set" plunger had come off and was always making the "Set" connection since it couldn't retract. I reattached the brass piece to the plunger and on the test drive...yeehaa! I have a working cruise control.
I thought I should give back for all the help others have given, albeit in bits and pieces all over the net, by gathering all I had learned into one place and posting it here. To that end, I have drawn up three diagrams relating to the switch and harness, but haven't yet finished the rest.
Still, if you have done all the other tests on the vacuum motor, and Duh! verified the fuse is good, you might start suspecting the switch.
Here's a link to those diagrams: ecapmiill.home.comcast.net/cc.html
Hope you find it useful,
Jim
