Fitment 2001-2004 Ford Ranger What is a Fan Clutch? The clutch fan is equipped with a fan clutch between the pulley and the fan blade hub, and the working state of the fan is adjusted through the separation and engagement of the clutch. This not only ensures the normal operating temperature of the engine, but also reduces the power loss of the engine and reduces fuel consumption. How to Detect a Faulty Fan Clutch? .