Thread: Can't fix the cruise control

The hoses are always the most likely culprits, when I was trying to get mine going, I pulled off the trim panels under the steering wheel, took the vacuum hose off the brake pedal switch and using my mouth, sucked air to create a vacuum in the hose.
If that holds, the hose is probably ok.
I connected a bit of vacuum hose directly to the bellows and was able to watch the bellows compress and hold using the same technique.
While you are in the footwell, carefully take off the vacuum switch and check that is working, it should hold vacuum and release when you move the switch in and out.
I had to replace mine, was only about $20 for that switch.
The light could just be a blown bulb, but could also indicate a faulty ecu.
Make sure the two short hoses on the bellows are sealing properly, poleonpom used cable ties to seal his properly.
There is a pretty easy electrical test you can do, you just need 3 wires with alligator clips on the end, I made some up very cheaply with bits from Autobarn.
Here's a link to an earlier post I did outlining this test:Cruise control fixed!
Hope that is of some help, or at least a starting point!
Good luck with it, Pete.

When i got my P38 it had a new radio fitted. Could replacing the old radio effect the connections for the cruise control. I hear somewhere this could be a cause.

When i squeeze the bellows and hold my fingure over the bottom hole, this one has no hose on it, the bellows stays closed, take my finger of and it opens and air comes out.

I am trying everything i can think of.

Originally Posted by PeterH

The hoses are always the most likely culprits, when I was trying to get mine going, I pulled off the trim panels under the steering wheel, took the vacuum hose off the brake pedal switch and using my mouth, sucked air to create a vacuum in the hose.
If that holds, the hose is probably ok.
I connected a bit of vacuum hose directly to the bellows and was able to watch the bellows compress and hold using the same technique.
While you are in the footwell, carefully take off the vacuum switch and check that is working, it should hold vacuum and release when you move the switch in and out.
I had to replace mine, was only about $20 for that switch.
The light could just be a blown bulb, but could also indicate a faulty ecu.
Make sure the two short hoses on the bellows are sealing properly, poleonpom used cable ties to seal his properly.
There is a pretty easy electrical test you can do, you just need 3 wires
with alligator clips on the end, I made some up very cheaply with bits from Autobarn.
Here's a link to an earlier post I did outlining this test:Cruise control fixed!
Hope that is of some help, or at least a starting point!
Good luck with it, Pete.

In the picture with the arrow, there are two like arms sticking out the back of the bellows. Should they both have hoses on them. Mine only has a hose on the top one, do you get what i mean.

I think i see the problem. If the two pipes, thats what i call them, at the back of the bellows should have short hoses on them, then i am missing the bottom one, thats why i can hear air coming out when i press the bellows.

Where should the bottom of the two small hoses go. This could be my problem.

Yes this is about my cruise again.

You must forgive me as a new owner, i dont know the name of the various parts, yet.

Underneath the bellows, that has the cruise cable and to which one of the small hoses goes, there is another little pipe thing thsat has no hoses going into it. It looks like a small sealed box of some sort, should bothe little pipe things have hoses connected to them. The top one is from the bellows things, but what about the bottom pipe, i guess you are as confused as i am but i cant think what else to call these two pipes.

I may have to give up and buy a Jeep.

Hi Mate

Any chance you can post a pic?

Otherwise i could post a pic of my setup and see if we can identify the pipes

Steve

Its not on the bellows, its that little box underneathe the bellows.

When i squeeze the bellows air comes out, is this right, or is there a leak in the bellows.

A pic would help.

I don't know if it's the same as a D2 but one of my hoses fitted to a ver short, shrouded nipple and was split down inside the shroud and couldn't be pulled without tearing the hose. Had to completely dismantle the unit body (there's an abundance of very little in there) and I found that the seal between the body halves was damaged. It was leaking vacuum between the body halves (after fixing the hose). Got some straight o-ring rubber and made a new seal.