The drum will turn for 30 seconds to a minute and stop after a few minutes it will run for a short time and stop. I have unhooked the exhaust vent thinking there was a clog and it still happens.

Tear down the unit and clean it because it's clogged up with dirt. You will have to clean every little section or you will be wasting your time. It's a good idea to replace the belt and grease the bearings with white lithium grease.