There should be two wires going to the motor. The power goes through one when it goes down, and the other when it goes up. All that happens is the polarity to the motor is switched to make it run in a different direction.
If you haven't already, check both wires when it isn't working. If there is power, replace the motor. If there isn't any power from the switch when it goes up, the switch is bad.
Let me know what you find.
Monday, November 15th, 2010 AT 1:48 AM