My '99 CTD 2500 w/auto trans has a problem with the cruise control disengaging unexpectedly. At first it happened upon hitting a bump at speed and now it will sometimes disengage at will. What should I look for in trying to diagnose the problem? Any suggestions? Thanks!

 

I would start with looking at the brake switch. It's one thing that will disengage your cruise control and it is something that goes out once in a while.