Step 2 test the thermostat.
How to test attic fan thermostat.
Switch off the power of the attic fan and remove the power cord.
If the fan turns on the motor is still good.
Once done test that the motor still works by plugging the motor into an extension cord that is connected to an outlet.
Step 1 test the fan motor.
Note down the wiring before proceeding to remove it.
Turn the attic fan off and unplug the motor from the thermostat.