Faulty Fan Relay: The fan relay is responsible for supplying power to the fan motor. If the relay is faulty, it may not be sending power to the fan, even when the coolant temperature switch is functioning correctly. Check the fan relay and replace it if necessary.
Wiring Issues: There may be an issue with the wiring between the coolant temperature switch, fan relay, and fan motor. Check the wiring for breaks, loose connections, or corrosion, and repair or replace any damaged wires.
Faulty Fan Motor: The fan motor itself could be faulty and unable to turn on even when receiving power. To check the fan motor, apply 12 volts directly to the fan motor terminals. If the fan motor does not turn on, it is likely faulty and needs to be replaced.
Fuse Issues: Check the fuse that supplies power to the fan circuit. If the fuse is blown, replace it with a fuse of the same amperage rating.
Computer Issues: In some cases, a faulty engine control unit (ECU) or other computer module may prevent the fan from turning on. If none of the above solutions work, it is recommended to have the vehicle diagnosed by a qualified mechanic who can check the computer modules for any issues.
Note: Before performing any electrical work, ensure that the vehicle's battery is disconnected to avoid any electrical accidents.
