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		Our switch is a two-wire design, with one of the wires a ground.  rblong's hint is reasonable if you ground out the blue wire.  If the fan starts, check the ground wire, although it's an unlikely problem because that ground connection is shared by the headlights. 
		
	
		
		
		
		
		
		
		
		
		
	
		
		
	
	
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