Thermal Switch Test

Thermal Switch Test

The motor will not power-in if the thermal switch is open or if its terminals are in contact with the motor case. The switch should normally open when the temperature at the motor brushes reaches 205+ degrees C (400+ degrees F).

If the Thermal Switch is suspected to be failing check the following:
1. Disconnect the switch.
2. Measure the resistance of the switch at the electrical connector.
3. If the switch is open at room temperature then replace the motor.
4. If the switch is closed then the switch is good.
5. Check for resistance between both terminals and the motor case.
6. If the resistance is less than 1 megaohm then the winch is grounded. Replace the motor.