crwdns2890332:0Doesn't actually turn offcrwdne2890332:0There is a main switch on the lower left side of the speed control. The black wire plugs directly to it. I found the fixed contact bent upward so far that the movable part of the switch couldn't move up far enough to break the circuit. The fixed contact appeared to be bent up. I bent it down so that the contacts separated about halfway between stir and off. It now works perfectly.