The radiator fan is a critical component of the engine cooling system positioned behind the radiator. Its primary function is to pull air through the radiator core to dissipate heat from the coolant when the vehicle is stationary or moving slowly. While airflow from driving cools the engine at highway speeds, this fan ensures the engine does not overheat in traffic. It is controlled by the vehicle’s computer or a thermal switch. Failure of this part often leads to rapid overheating during idle.