The Fan Clutch: An Important Part of Your Vehicle's Cooling System

Internal combustion engines (ICEs) generate a heat during use. When driving, your vehicle's engine will burn gas and air. Hot combustion gases are created as a byproduct of this process. Fortunately, vehicles today are equipped with cooling systems to regulate their internal temperature. One of the most important parts of your vehicle's cooling system is the fan clutch.

What Is a Fan Clutch?

A fan clutch is a temperature-sensing device that regulates a cooling fan. Most vehicles have one or two belt-driven cooling fans. You can find them near the radiator. Cooling fans draw air over the radiator -- as well as the air conditioning condenser -- to remove heat. A fan clutch is a device that tells the cooling fans when to run and when not to run.

How Fan Clutches Works

Most fan clutches fall under one of two categories: thermal or non-thermal. Thermal fan clutches consist of a spring that changes its size in response to the temperature. When exposed to heat, thermal fan clutches will expand. As the temperature to which they are exposed drops, thermal fan clutches will contract while becoming smaller.

Non-thermal fan clutches work by maintaining a partially engaged state at all times. They aren't as common as thermal fan clutches. With a non-thermal fan clutch, your vehicle's cooling fan or fans will run at all times

The Importance of a Fan Clutch

Fan clutches are important because they work in conjunction with cooling fans to regulate engine temperatures. Cooling fans must spin to remove heat from the radiator. If you're sitting idle at a red light, the fan clutch will engage your vehicle's cooling fans so that they spin. 

Most cooling fans, though, will spin automatically as you drive. Driving will force air through your vehicle's grille where it causes the cooling fans to spin automatically. The fan clutch will disengage the cooling fans in instances such as this. It won't consume power to spin the cooling fans. Rather, the fan clutch will allow your vehicle's driving speed to spin the fans.

The fan clutch will also disengage your vehicle's cooling fans if the engine has dropped below its operating temperature. Engages are designed to operate at a specific temperature (or a temperature range, at least). Upon dropping below this temperature, the fan clutch will disengage the cooling fans. This means the cooling fans will stop spinning, in which case the engine will warm back up to its operating temperature.