Speed control problem

NavigatorV8

New member
Hi there, i´m new here. My Name is Michael and i´m live in Germany. My ride is a Navigator from 2004 and i will start with my problem:

Since a few days my crusie control is w/o function.
I am very to grow desperate. Thats what i tried:

  • entering self test, everything --- passed
  • measured the resistance and voltage between spring clock and PCM --- passed
  • measured voltage and resistance between PCM harness and ground --- passed
  • measured voltage and resistance at servo control --- passed
  • checked the switch at brake pedestal --- passed
  • checked mechanical parts like control cable --- passed
  • connected a VCM via OBD2 and read the DTC, was clear

Anybody has an idea, what can it be? It is very, very important for me.
Thank you so much for help
 

tixer

Lincoln Evangelist
Welcome Michael!

I have recently had some similar frustrations with my '99 Town Car. After performing the same troubleshooting you have, I noticed if I lift up on the brake pedal with my foot while activating the speed control, it will operate, but if I hit even the smallest bump on the road, the system will immediately cancel.

My theory is this. I suspect that one of the two switches attached to the brake pedal has some kind of calibration mechanism to it. If it is too far out of range in either direction, the cruise fails.

I think this because the speed control did work properly until I removed both switches from the pedal, and then reinstalled them, as part of another project.

Upon searching for a picture of the switch in question, I found the following article. The blue and black "deactivator switch" referenced in the second section of this article is the same one I suspect as causing the problem on my own car.

http://www.denlorstools.com/autoblog/2010/12/ford-cruise-control-inoperative-easy-self-test/

The article indicates that it can be bypassed for testing, which seems like it may be worth trying.

Good luck, and welcome again to the forum!
 

NavigatorV8

New member
Mike, very helpful link. But all topics i checked. And the idea with the brake pedestal switch was mine too. I remount the switch and operate it during drive by hand, but no speed control.... :-(
 

tixer

Lincoln Evangelist
Is it safe to assume that you have checked the fuses as well? My research into my own vehicle indicated that there could be up to two different fuses that operate the cruise control system.

The fact that your Navigator passes all of the self tests and resistance tests is confusing. They seem quite complete. I'm afraid I don't have many other suggestions to offer, as much as I wish that I did.

Please do hang around, perhaps some of the other members here will have some ideas as well. The vast majority of our members are far more knowledgeable than I.
 

NavigatorV8

New member
yes,that was the first, what i checked. The Navigator has four fuses and one relay, but it isn´t checkable, seems is inside the central junction box
 
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