Cruise control
 

My 97 has a problem with the cruise control. First off, it won't set between 60 and 69 mph. After your at 70 or above or 59 or below it will usually set the first try. If I'm empty and set it it climb about 10 mph and then kick itself off and not pick back up where it was set. If I am pulling a trailer and set it then it will seem to stay wherever I put it. It was where I could set it accelerate a little and then let it go back to the setting point and it would work fine. Any ideas?

Do you have ABS?

In the rear end yes. Not in the front end.

Well... that's sort of weird. I only ask because one day I was trying to diagnose a brake problem and unplugged my ABS, and one of the things I lost was the cruise control. I have no idea how these two systems interact, but if you have a week spot in the readings in that speed window maybe? No clue. I've never heard of this, usually cruise control problems with these trucks are surging, delayed response, things like that, due to being turned up way stronger than Chrysler electronics can adapt to. Usually restricting the vacuum line going to the cruise clears those issues up, but I don't think it would work for whatever this is. If I have some time today I'll check my service manual and see if I can find anything.

Thanks. It has done this since before I changed rear ends so I'm thinking it's not related to the abs.

The issue would be with the ABS computer. I don't know how different the setup was between '97 and '98 though. And only in the rear? Hm. Did you delete the front, or was this some weird Dodge thing that's commonly known but I haven't heard of it before? (it never ceases to amaze me when- despite my OCD- this situation unfolds yet again)

I didn't delete it. Their are no sensors or tone rings that I have found on the front end. My cousin and I both have 97's and neither have front abs. The only wires going to the front end are in the 4x4 cad.

So, weird commonly known Dodge thing I somehow missed then. Hm.

What else could be causing the problem besides abs?

Did it ever work right?

Yes. It seems like it has gradually gotten worse. For a while it would set and start to accelerate and if I accelerated with the pedal up about 7-10 mph and then let off it would settle back to where I set it and stay there. It has quit that now also.

I think you may have two separate issues with it. Mine began doing that when I started turning up the pump. It would also realize I'd reached a hill when I was halfway up it, at which point it had to hammer down twice as hard to get back up to speed. Then it wouldn't realize it was over the hill and cruising down the back until it was doing 30mph higher than it was set at. Annoying to say the least, more like cruise out of control. But as I said earlier, putting a restriction in the vacuum line to the cruise down by the headlight helps immensely, although I didn't do it myself and I'm not entirely sure exactly how my guy did it. But I think you have something else going on as well, because that dead spot is a new one to me.

Great! I always like to be original! Any idea what would be a good restrictive device? I would think it would be to small for any kind of valve.

I'll ask my guy what he puts in there. I've never been able to get an intelligible answer out of him.

Hm. He said he uses a mig welding tip. I'm not sure how one would go about fitting that in there, but then, I've never pulled the battery and looked at it.

I've got those. I guess I can try it and see what happens. Thanks for the info.

Let me know how it goes, because I'm still scratching my head a bit over it.