What is a radiator fan?

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A cooling fan is a vital component in a car cooling system, that helps takes away all heat absorbed from the engine using coolant. All its work is done through the radiator by pushing or pulling air through the radiator. A radiator cooling fan is located in front of a car and it’s electrically powered, well, depending on the vehicle design.

Functions of radiator cooling fan

Below are the major functions of the radiator cooling fan:

1. The primary function of a radiator cooling fan is to take away excessive heat absorbed by the engine. The coolant absorbs the heat and goes into the radiator where the heat is blown away.

2. The system is functional when the engine is stationary, where air can’t move through the grille.

3. Cooling fans help to obtain external airflow when moving too slowly.

4. Electric cooling fans control the temperature of the vehicle as it turns on and off based on the engine temperature.

Components of radiator cooling fan

In this article, we are explaining both electrical and mechanical cooling fans. As earlier mentioned, the mechanical cooling fan is found on older vehicles, while electrical fans are found on new vehicles.

The components of the mechanical cooling fan are just a cooling fin mounted on the engine, powered by the engine crankshaft. Though it’s mounted on a machined cup with bolts. This cup is allowed to rotate with the engine pump and it serves as a pulley to the drive belt that powers other essential components of the vehicle

The electrical radiator cooling fan is a standalone device with various parts. The parts include a cooling fan shroud, motor, and cooling fan or fan. The cooling fan shroud serves carriage because the other parts are mounted to it and it’s placed directed to the radiator. Other components will be explained in the working principle section of the radiator cooling fan.

Types of automobile cooling fan

Below are the types of radiator cooling used in automobile engines:

1. Mechanical radiator fans: A mechanical radiator fan is an old design of automobile fans but is still used today. It’s mounted directly to the water pump pulley on the engine and is driven by a belt. The power that rotates the cooling fan is obtained from the engine crankshaft, so when it rotates the fan also rotates.
These types of radiator fans are used in many applications apart from automobiles as they are less complex and just require mechanical power to rotate them. The mechanical radiator fan is always on as far as the engine is running. Depending on the design, it either pulls or pushes air to cool the coolant in the radiator.

However, fan clutches allow the mechanical cooling fan to go “off and on” when required. That’s according to the temperature of the engine. The two types of mechanical cooling fan clutches are:

1. Viscous-drive clutches: These types of clutches work with a fluid coupling, allowing the fan to engage when the engine reaches a specific temperature. These fan clutches contain a bi-metallic sensor that works like thermostats. If the engine is cold or at cold starting, the clutch is disengaged, and the fan freewheels. When the engine heats up, the bi-metallic sensor allows the viscous coupling to engage. This causes the pulley to spin along with the fan attached to it.

2. Electric fan clutches: The electric fan clutches work similarly to the vicious types, but they can be switched on and off by the engine control unit (ECU) depending on the current engine condition. This gives it more turns up than the first type as it allows the operation of mechanical cooling to be tightly controlled.

2. Electric radiator cooling fan: An electric cooling fan is a standalone device that is powered by the engine’s electrical system rather than the engine. the system is mounted directly to the radiator for effective cooling, perfectly tighten with bolts and nuts. These types of radiator cooling fans use a DC motor that switches on and off depending on the engine temperature. This is achieved either by the engine control unit or by a coolant temperature switch. The device can either be mounted at the front or back of the radiator along with the integrated fan shroud.

3. Single Radiator Fan: As the name indicates, a single radiator fan is a one-fan assembly. It’s the most common configuration and used in many different types of cars. A single radiator fan is not suitable for some applications, though. These include large engines that require a lot of air to take away the heat produced. Modified engines, too. In such situations, an assembly consisting of two fans is often used.

4. Dual Radiator Fan The dual radiator fan is a set of two fan assemblies. They are usually used for electric fans and when the engine is large and cooling needs higher. For that reason, these types of cooling fans are most common on large vehicles or those with modified engines. The setup allows more air through the radiator core for a more effective cooling effect.

Working principle

With the following explained above it’s obvious the working of automobile cooling fans is less complex and can be easily understood. Sure you now have a clear understanding of how the system works. But you still watch the video embedded below to have more understanding.

Symptoms of a bad or failing cooling/radiator fan

Below are the signs of bad and failing cooling radiator fans in automobile engines:

1. The cooling fan will not come on: The common and obvious symptom is when the cooling fan not working when the engine ignition is on. This problem often occurs from the fan’s motor or the electrical connection of the system. when this happens, overheating takes place as the hot coolant will not be properly cooled. Drivers often notice this issue when they did not hear the component sound when the car ignition is on.

2. Blown fuse: Most vehicle electrical components work with a circuit fuse which a cooling fan is among. If this fuse has blown or burned, the cooling fan motor stops working, which is one of the common ways that disconnect the device. Sometimes, failing or surging of the motor will cause the fuse to blow so that other components will be prevented from damage. The fuse must be replaced to bring the cooling fan back to life.

3. Vehicle overheating: This is another common sign of a faulty radiator cooling fan; the engine begins to overheat since the source cooling is down. This also occurs when the cooling fan motor burns out or the fan is disabled. The motor is what spins the blades to push or pull air through the radiator. So, if the motor fails or is weak the blade will not spin or generate enough air to cool the hot coolant.
In modern vehicles, cooling fans are designed with thermostats that come on and off depending on the engine temperature. Thus, once a certain temperature is reached, the fan is supposed to start working. If it refuses to work, the engine temperature will continue to increase until the engine overheats.

Thank you for the detailed explanation. I got dc 07, only to realise thermostat was alrrady removed and the two fans connected directly. Thus, temp gauge doesn't ever get to middle. Can I buy replace the thermostat ? Also, in told only one fan suppose to blow, that the 2nd one only comes on with using AC. Is that true