Radiator cooling fans are used in a cooling system when the airflow through the radiator is not adquate. In this case, the fan will switch on and draw air through the radiator.

A defective cooling fan may cause severe damage to a vehicle and affect its drivability. When such a part becomes faulty it should be replaced as soon as possible. One sign of a faulty radiator cooling fan is when the car regularly overheats, as indicated by a gauge rise on the dashboard. Other signs include when the ""check engine"" warning light is lit, or when the cooling fan fuse blows.