I have a 1991 GMC Sierra 1500. The other day the cruise control kicked out on it's own. I pressed resume and it was fine. I pressed the brake to kick out the cruise and it never worked again after that. I have never had any problems with it until now. Any thoughts?

if both wheels are not turning look into the diff. but if only one tire is seized check for a brake problem.

check the brake switch on the upper arm of the brake pedal, if its bad your cruise control won't work because the truck thinks your pushing the brake pedal. I had the same problem in mine, it's a $30 part that takes about a half hour to fix

Your cruise won't engage because your brake lights are on permanently.
These are on permanently probably because your brake switch is faulty.
It's located near the top of your brake pedal.

Hold your foot under brake pedal pulling up on it if this cures problem adjust brake light switch up a ways on fire wall side of pedal arm

Grinding noise , wheel bearing is bad . Take it to the repair shop right away .

have you tested your brake switch,it could be your brake switch.looks like you have done about everything else.

Check your cruise control fuse or relay. It will be in your owners manual. If fuse is good than the cruise itself may be faulty. Check continuity on cruise controler itself. If there is power, than the controller itself is bad and need to be replaced. If there is no power than it may be a faulty switch.

check rear wheel sylinders for moister. an indicator for a leak. replace it then bleed brakes. refill resivore should be fine then. check front calipers also or leaking line.

normally the brake switch is the issue with these trucks. it is located under the dash where the brake pedal meets the linkage to the brake booster.

Or you could just pull the fuse for the abs and not have abs but you won't wreck from pulsating pedal.