Fitment: 2004-2012 Chevrolet Colorado 2004-2012 GMC Canyon 2006 Isuzu i-280 2007-2008 Isuzu i-290 What is a Fan Clutch? A fan clutch is a thermostatic engine cooling fan that can freewheel at low temperatures when cooling is not needed, allowing the engine to warm up faster, relieving unnecessary load on the engine. As temperatures increase, the clutch engages so that the fan is driven by engine power and moves air to cool the engine. .