Step 2 test the thermostat.
How to test attic fan thermostat.
Note down the wiring before proceeding to remove it.
Step 1 test the fan motor.
Switch off the power of the attic fan and remove the power cord.
If the fan turns on the motor is still good.
Turn the attic fan off and unplug the motor from the thermostat.
Note down the temperature settings for later reference.