Fitment 2010 Dodge Ram 2500 2010 Dodge Ram 3500 2010-2013 Ram 2500 2011-2013 Ram 3500 2010-2013 Ram 4000 2011-2013 Ram 4500 2011-2013 Ram 5500 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? .