My 95 2500 Cummins 4x4 auto trans has an intermintent problem in my cruise control. Most times when the on button is selected then set there isn't a response- no speed capture. On occasion it will capture the speed but after two minutes or so it will disconnect. I have cleaned contacts under the hood but before I look further I would appreciate some direction. I know there have been posts on the cruise control in the past, but I havn't one similar to my problem.
Thanks

 

Check for vacuum leaks on the plastic lines that go to the cruise servo it is common for them to get a hole rubbed in them and do exactly what you describe.

 

I checked the lines and found no leaks. When I disconnected the first line i heard the vacuum air equalize. Would the servo be next and how is that checked? There appears to be no external damage and the battery box has no acid leaks.
Thanks for all responses.

 

The problem is probably with your steering wheel. I had the same problem. The On switch would not stay down the nub that holds it down is worn off, som when you are driving it will wiggle its way up and shut off the cruise. Try wedging a little piece of paper or something under the bottom side of the switch and see if that fixes it...

 

I tried holding down the on button but the cruise shut off after a minute or so. Any other ideas?

 

Try this. While trying to set put your foot under the brake pedal and apply upward pressure. If it catches, try adjusting your brake light switch. That is what I had to do to my 95.

 

I lifted foot under brake pedal while setting cruise. Unit disconnects after a minute or so. The unit will only capture speed once in the trip. All other attempts to get it to capture after the first wont work.
So far I have checked the vaccuum lines, on/off buttons and brake switch. Any other suggestions?
Thank to all.

 

I found some corosion on the outside of the servo. Replaced with new ($77.33) No change - still cuts out after a minute or so. Local dealer wants to check wires, switches and module. I will post findings.

 

Problem solved. Dealer found short in brake switch. Switch would cut off power to servo after a minute or so after first start-up. $21.50 for switch $151.99 for labor to trouble-shoot and swap switch (ouch)! I drive 1000 mi. a week so well worth it I hope this will help someone else with a similar problem. Again, thanks to all who offered help. I will use this site and recomend it to all my fellow Dodge Cummins owners and operators.