My cruise control has been acting up lately. A couple of weeks ago it began losing MPH under odd conditions--it didn't always lose MPH, especially above 60, but it often did. Then yesterday it began accellerating on me. I'd set it at 55 and it hold 55 for only a short time before it would begin accellerating on its own, and keep going until I either tapped the brake or switched it off. Any guesses as to what's wrong?

 

When that happened on mine I was told to set the cruise at 60, then shut it off then reset, do it 10 times in a row and it resets the computer, it worked on mine

 

Thanks. I'll try it.

 

HEY... it worked! Thanks for the tip.

 

Well, it's back to acting badly again. If I'm on level highway, the C.C. keeps the speed, but if I go either up hill or down hill, the C.C. speeds the truck up. Sometimes if I hit the "pause" button the truck rapidly accellerates. I have reset the computer using the "10 second" process multiple times, but I don't think I've done it 15 times in a row. And I can only do it on level highway, because on hills, either up or down, the C.C. accellerates and that blows my 10 second reset.

 

Could be the clockspring in the steering wheel. There is rumor that this is a warranted factory/dealer fix since it relates to the airbag and safety restraints....I'd call your local dealer and inquire.....if not, they aren't that hard to replace, just kinda finicky.

Kurt

 

My cruise control had stopped working some years back, and I finally took it to my mechanic who is very knowledgeable about our trucks... he owns 4 or 5 himself, and his dad, also a diesel mechanic, owned 3... anyway he put a new clock spring in and it worked great for about 6 months. I'll take it back in and ask him if he knows of a fix.

 

The heartbreaker of owning these is the fact they do wear out, mostly due to the plastics going to brittle garbage.....If the late 60's early 70 trucks had our metal coatings! And the Cummins option.....

 

Yep. My cupholder fell out of the dash a few years ago, and I can't seem to find anything to anchor the screws to. And my dash fell in, but I solved that with a dash cover.

 

Sir my truck does exactly the same thing . I thought I figure it out eventually but no so . It's weird and I thought what in the hell can cause all of these problems. I checked everything I know of . I was thinking may be its the pcm but I don't know for sure . Thanks again for your help

 

Where is the cruise control memory stored? In the PCM? Does anyone know. And if its in the PCM, can the PCM be reflashed to fix the problem?

 

Robert did you get this problem resolved.. As most things my cruise worked good until it did not . I have a 95 4x4. That I been working on since I retired. It now had around 220 k or a bit less miles. I have gotten my cruise to work again when i replace the steering wheel switch assembly. A bit later it started acting as you stated . I dont think i have a vacuum problem. I also have a new servo . . I got to a point I thought it may be a bad pcm .. years ago I had all kinds of electrical problems and I replaced the pcm and it fixed them . What a learning experience..

 

I have not gotten the problem resolved yet. Monday I needed to go on a short trip, and tried doing the 10-second/60 mph fix, but every time the truck slowly sped up (with the cruise control on).
Where did you get your new servo? How much was your pcm?

 

ROBERT I got it from.mopar several years ago . As I was trying to fix the truck and I asked and the reply was O the pcm is probably not the problem on the forums . Yea it was . I had this old truck for a long time . Remember the conversation about how great the single disc convertor was lol. By the way Robert my brakes got better when I installed a hydroboost system lol... I replaced the servo I bought on e bay new old stock .. I don't have any vacuum leaks ... My problem is the cruise works but gains speed sometimes. Or drops off going down a hill . It works better on the highway at higher speeds. As many things my cruise worked good intill it did not ... the servo you can pull apart and check the valves for proper sealing ..the gaining speed is not a constant thing only every now and then . I busy now changing the front axle now to allow for 3rd gen brakes

 

Thanks Workinman. Mine gains speed almost every time I turn it on, but especially over 65. If I am on completely level ground, and I turn it on at 55, sometimes it holds for the 10 seconds it takes to reset the memory. But I've never been able to do 15 in a row, without stopping the truck--its just too hilly here, with long, flat stretches being few and far between.