Hi Chris,
Before you replace the motor I would recommend to test it for continuity and check if 120V is coming to the motor.
Remove the ice bucket and the ice maker.
Remove the bucket shelf. Remove the wires from the motor and check the motor for continuity. If the reading is about "∞" - the motor is bad.
Depress the light switch on the door frame and check for 120V across the motor wires while the ice dispenser is calling for the ice.
If there is 120V then the motor has to be replaced.
If there is no 120V then possible problem with the dispenser control board.
Here are the break down diagrams for the GE refrigerator
Model TPX21BRXAWW
Gene.