I would suspect the canister motor. The armature is arcing and causing to much current. This condition will quickly make the thermo-protector open up and shut down the motor. Take note of the sound and smell of the motor's exhasut air when you can get it to run. It probably will smell burnt and sound inconsistant, like a cracking or popping. Another indicator is the exhaust filter. Black dust is a sign of a shorted armature and cooking the carbon brushes.
www.vacuumcleanerhelp.com, April 2009
