Hayden® 1707 - Non-Thermal Engine Cooling Fan Clutch

A fan clutch is the part of the cooling system that powers up the fan blades. Each time your engine gets too hot, the clutch fully engages the fan. This allows the fan to blow the right amount of air onto your radiator for maximum cooling. Once the operating temperature of the engine goes down or the engine starts operating at a normal temperature, the clutch partially disengages the fan to save more power.

There are two types of fan clutches, non-thermal (also called centrifugal clutches) and thermal. Non-thermal clutches operate based on the shaft speed of the water pump. At low and idling speeds, the clutch allows the fan blades to turn at almost a 1:1 ratio. At high speeds, the silicone fluid contained in the clutch loses its ability to transfer the energy from the shaft to the fan clutch body (and therefore the fan), and the fan is then allowed to almost free-wheel, removing its load from the engine. Non-thermal fan clutches perform well, spinning at about 30-60% of the water pump speed. Plus, they cost less than standard thermal clutches. If your fan spins excessively when the engine is stopped, the A/C performance is poor at idle or low vehicle speeds, or you feel vibration that increases with the engine speed, these are the signs of the failed fan clutch. Don't put your vehicle at risk and opt for a premium replacement fan clutch by Hayden.