What is the reason why the car's AC fan does not turn on?

[DeMalachi]

The reasons why the car's AC fan does not turn on are as follows: 1. Relay failure: If the relay fails, the car's radiator fan will not work. If the water temperature is normal but the radiator fan still does not work, the issue may lie with the fan's relay. 2. Poor contact: Poor contact in the main control switch or damage to the fan motor coil. Use a multimeter to measure the contact resistance of the main control switch. If the resistance is too high or zero, repair or replace the switch. 3. Loose screws: The fastening screws between the fan motor and the fan blade may be loose. Tighten the fastening screws. 4. Open or short circuit: The fan capacitor may be open or short-circuited. Check the capacitor and replace it with one of the same specifications.