Cruise Control

Check to see that the brake lights work properly. The cruise system relies on the brake light switch for it's 'unlatch' signal. Check your fuses. If you ride the brake pedal with your left foot, don't do it anymore, you will have cruise problems and maybe some driveability problems if you do. Not meaning to be a wiseguy, but I've gone on many test drives with customers who insist on riding the brake with the left foot. Had to say it. Check that the cruise cable or linkage to the throttle is still connected. Here's a directory link for you: http://repairpal.com/gmc-repair-in-gallatin-tennessee