Why does the cooling fan fuse blow in the Mustang?

The most common reasons for the cooling fan fuse (radiator fan fuse) blowing are:

1. Short circuit: a short circuit in the wiring that powers the cooling fan can cause excessive current flow, which blows the fuse. Short circuits can be caused by damaged, frayed, or exposed wires coming into contact with metal parts of the vehicle.
2. Faulty cooling fan motor: a damaged fan motor or one with defective internal components can increase the demand for current, which can overload and blow the fuse.
3. Cooling system issues: if the engine overheats or if there are problems with the cooling system, the radiator fan may run more than usual, increasing the load on the fuse.
4. Incorrect fuse: if the fuse has been replaced with one of a lower amperage than specified by Ford, it is more likely to blow even under normal operating conditions.

If the cooling fan fuse is blown, it’s important to identify and fix the cause of the overload before replacing it, to prevent the new fuse from blowing as well.

Other causes of cooling fan failure in the Mustang

In addition to a blown fuse, these are the other most common causes that can prevent the cooling fan from working:

1. Faulty cooling fan motor: if the cooling fan motor is broken or worn out, the fan will not turn on, which can lead to engine overheating.
2. Faulty cooling fan relay: the relay is the switch that activates the cooling fan when the engine reaches a certain temperature. If the relay fails, the cooling fan will not receive the signal to turn on.
3. Defective coolant temperature sensor (ECT): this sensor monitors the coolant temperature and sends the signal to the fan relay to activate the fan. If the sensor is defective or not working properly, the fan may not turn on when needed.
4. Faulty thermostat: a defective thermostat that does not allow the engine to reach the proper operating temperature can prevent the radiator fan from activating when it should. This happens because the cooling system does not heat up enough to trigger the fan.
5. Engine Control Unit (ECU) problems: in modern vehicles, the ECU controls many aspects of engine operation, including the radiator fan. A problem with the ECU or the software that controls it can prevent the fan from turning on.
6. Low coolant level: if the coolant level is very low, the temperature sensor may not correctly detect overheating, preventing the fan from turning on.