- Check if there is a problem with the fan motor. You can do this by disconnecting the fan motor from the power supply and applying 12 volts directly to the motor. If the motor works, then the problem is with the power supply to the motor.
- Check if the ground connection between the fan motor and the body of the car is good, this can be done by using a grounded jumper wire to connect the negative terminal of the battery to the metal housing of the fan motor and observe the operation of the fan, or by connecting a multimeter set to measure DC volts between the fan motor housing and the battery negative terminal.
- If the motor does not work, then you will need to replace the motor.
- Check if the wiring between the temperature sensor and the fan motor is intact, this can be done by using a multimeter set in the continuity, resistance, or beep mode to check for continuity between the sensor connector terminals and the fan motor connector terminals.
- Check if there is a problem with the fan switch. You can do this by bypassing the fan switch and connecting the power supply to the fan motor directly if the fan comes on then the problem is with your switch.
