I have the same problem with a 2001 Durango Sport. Cruise control comes on for a short while, less than a minute, and then goes off. Will not come on again until you shut off the engine and restart it. I also found out that when I turn on the cruise control, all three braked lights come on, and then gradually dim until they and the cruise control go off. I have replaced the clock spring and stop lamp switch on the brake pedal with no fix found yet. Good luck.
Friday, July 6th, 2007 AT 9:24 PM