The fan lowers the temperature of the engine. The cooling fan motor is an electric motor that turns the fan blades. When the vehicle is in traffic or under heavy load, the engine relies on the fan to cool itself.
Some vehicles may use multiple electric fans for better control of the cooling system. For the most part, electric cooling fans are controlled by the same computer that controls the engine. However, in some engines, the fans are turned on and off by a temperature-sensitive switch mounted in either the radiator or elsewhere in the cooling system.
The electric cooling fan is mounted on the radiator. Failure of the fan motor usually causes overheating. A fan that runs constantly can cause poor fuel economy, unwanted noise, and may run the battery out.
The cooling fan motor is operated by a switch located in the radiator or engine's cooling passages. The electric cooling fan turns on when the engine's coolant temperature reaches approximately 195 to 210 degrees Fahrenheit.
The cooling fan assembly is attached to the radiator. To replace the cooling fan motor, the cooling fan assembly must be removed. The fan blades are separated from the defective cooling fan motor and attached to the new motor. The assembly is then re-attached to the radiator.