I have a 2003 F150 bought new with 38000+ miles. For some time, the cruise control only worked sometimes, with no identifiable reason. It has the recall pressure switch and fused link installed, and all 3 brake lights work. Although the truck is seldom used, the cruise now very seldom works when asked to do so. However, it sometimes actually does. I suspect that the cause of this lies with the Control Module. But Lacking access to a good wiring diagram and proper instrumentation, I have no way to verify this other than obtain another module and change it out. With the cost involved, and the uncertainty involved, I am not ready yet for that approach.

With all that said, is any one willing to offer advise?
Arnie

 

Click this, read the caption, follow the links:


(phone app link)

No, the module on the servo is not a likely suspect.

 

Steve Many thanks for the response. I am reviewing. In the interim, I am trying to figure out; a) on a day when the system decides to operate, all test will be positive, b) on a day when it will not operate, regardless of many, many attempts, how trustworthy will the system check be? Seems to me that there is an electrical/temp. problem involved somewhere in the system.
Arnie

 

When it's working, there's no point testing. When it's not working, the tests will reveal the problem (if you do them correctly).

 

Have you checked to be sure your vehicle is not covered under the cruise control recall? I don't remember all years and vehicles, but I for sure had a 1999 F-150 and a 2003 Ranger that had to be brought in for the recall. The failing parts can actually start a fire.

 

He already said:

 

I have now found that the set/excel switch is the fault. In order to replace, the air bag needs to be removed. I have read several reports, and watched several videos describing how to.
I am concerned that there is some disagreement in what is the safest method is. Anyone have advise?
Arnie

 

Remove the fasteners, lift it out, & unplug it. Set it on the ground FACE UP; either under the truck, or away from everything. But these airbags are NOT hypersensitive - they don't deploy without a specific signal to do so. I have a few in my junkpile, and they've been shoved, stacked, tossed, & transported for decades.

 

And don't forget to crawl all over the associated vacuum hoses. Move them around, lift them up, inspect carefully. Chances are there are some weak spots, probably some cracks, maybe breaking. Will eventually cause more problems than just cruise control. I have had that problem, back and forth to dealer, finally figured it out myself.

 

There are no vacuum lines for F-series cruise control after 1992.