How long does the cooling fan resistor last?

The cooling fan resistor is designed to remove heat from the engine coolant and from the air conditioner refrigerant. The resistor does this by drawing air through the radiator and air conditioner condenser. Belt driven fan…

The cooling fan resistor is designed to remove heat from the engine coolant and from the air conditioner refrigerant. The resistor does this by drawing air through the radiator and air conditioner condenser. The belt driven fan is mounted on a temperature controlled clutch and the cooling fan resistor draws in air as soon as the temperature is detected as too high.

The resistor controls the turning on of the cooling fan, and it usually turns on in stages. When you turn on the car, the engine heats up very quickly, so the cooling fan resistor turns on in stages. This helps to cool the engine evenly and keep the car running smoothly.

After the engine reaches a high temperature, which is already determined by the manufacturer, the switch indicates that the cooling fan resistor starts to run at high speed in order to force more air through the radiator. This provides extra cooling to the engine so it doesn't overheat. Depending on the make and model of your vehicle, you may have a second fan that provides more airflow for the cooling and air conditioning system. The second fan is also powered by the cooling fan resistor and always runs at high speed.

Over time, one or both of the cooling fan resistors can wear out or fail due to everyday use. If you suspect that the cooling fan resistor needs to be replaced, see a professional mechanic. If your cooling fan is being replaced, chances are your resistor needs to be replaced as well.

Because this part can fail over time, it's important to recognize symptoms that may require it to be replaced.

Signs that the cooling fan resistor needs to be replaced include:

• The cooling fan does not start at all
• Engine temperature rises to dangerous levels
• The cooling fan never turns off even if your car is turned off
• Your car overheats regularly

The cooling fan resistor is an important part of your cooling system, so running it too long can cause engine damage due to overheating and major repairs.