99western star 500hp 60 series detroit. cruise works fine when stoped and parking brakes applied.when i set it at hwy speeds computer says cruise set at 65 or whaterver i set it at but when i lift off the pedal it's notworking can anyone help
setting the parking brake and using the cruise to bring up the idle speed, does the cruise come off if you step on the brakes or pull the trailer arm? The micro switches in either of those spots could be open and won't let you use the cruise when the parking brake is off.
It has been 8 years since I had the same problem, with my det. I remember there being 2 switch/relays behind dash, behind the cruise control switch. they both affect the cruise. I replaced both of them. it fixed the problem. that was with a 11.1 ser 60. I cannot remember what they looked like. I do remember straight wiring one to a toggle switch to see witch one it was. I found out witch one it was but, decided to get both cause I figure if one went out, the other aint too far behind.