I would suggest with checking the brake switch first. It is a 2 circuit switch, which when the brake pedal is depressed, opens one circuit and closes the other. Release the pedal would reverse the operations of the switch.
Check the clearance between the brake pedal stopper and switch. Try inserting a thin piece of card board between the switch and stopper and test drive to see if the cruise works. If yes, either the stopper requires replacement or the switch has to be readjusted to get the correct clearance.
If you have a DVOM, testing the resistance would be the best option.
If the brake switch is tested ok, next you would have to test the control unit input as outlined in the latter part of first post.
Saturday, October 3rd, 2009 AT 9:15 PM