You are correct. By changing the power supply from one wire to the other, it changes the polarity of the power. Thus, the motor runs two different directions.
If you are getting power to both and the connection to the motor is good, the motor is most likely bad. NOTE: I assume the power is going from one wire to the other when you change directions at the switch.
Saturday, December 27th, 2014 AT 7:29 PM