The radiator fan (or fans) pulls cooling air through the car’s radiator. Positioned between the radiator and engine, cooling fans are particularly helpful when the car is stationary or moving at speeds too slow to force air through the grille. The advent of electric cooling fans, which turn on and off as needed, proved an improvement over engine-driven fans that slow down exactly when they’re needed most. A failed cooling fan can result in an engine overheating. These fans sometimes double as a cooling source for the cabin air conditioning’s condenser.