Cruise control don't cruise

[WayneIlfrey]

The cruise control on my '91 250 has never worked. My father bought the truck new and never really used it. I aquired the truck in '99 and he has never had it working.

I see there is a TSD on the website about this problem

Engine rpm fluctuates when the cruise control is engaged.

This bulletin is for non-intercooled (build date prior to 1/1/91) trucks. The bulletin involves replacing the vehicle speed control module with a recalibrated module.

Has anyone found a fix for this or will I have to go to my local overpriced dealer to get a new one?

 

[ETOBICOKE]

Cruse Control

Don't think that the TSB that you are refering to would cover your problem. Assuming that you have checked the obvious things, like the fuses and speedo drive, since your cruse does not work at all, the best place to look first is the brake light switch, it is also used to dis engage the cruse. Often it has been found with our trucks that the switch is out of adjustment and does not allow the switch to engage. If adjusting the switch does not help get your hands on a 91 service manual, all the information to trouble shoot the problem is in the electrical section #8.



Neil

 

[dshockley]

I had a similar problem on my early 1991 that I purchased a few months ago. The PO claimed that the cruise never worked. When I started tinkering with it, I got out on the highway and set the cruise(at around 65) and then let off the accelerator. The speed would drop until the cruise caught it at about 45 mph. After a little checking I discovered that the cruise cable needed to be adjusted. Once adjusted, it still "picks up" the slack very slowly and then only at about 5-6mph below the set point. It then stabilizes at around 2 mph below the set point. In late 1991 they changed the cruise set up. From the folks that I have talked with, the early 1991 set-up will be haunted by this poor response. Once it is set and stabilized it works great! It is kind of a pain, but it does it's job. Good luck.



Dan

 

[WayneIlfrey]

Thanks for your responses but...

My apologies. I said it never worked, I meant It never worked properly.

I have the very problem that the TSB is talking about.

I set the cruise at any speed and it just goes up and down up and down. It will not hold a speed. The thing will give you whiplash!



Any other comments would be appreciated.

 

[dshockley]

The po mentioned that he had this recalibrated module installed while the truck was still under warantee, so that should probably be your first move. There is also a tsb that discusses the way that you should engage the cruise to avoid the cruise module "learning" to over-correct.



Good luck,



Dan