I have a 2000 sportsman 500 4×4 that has been an awesome machine. Mainly use it to hunt. Two weeks ago it ran hot for the first time. I pulled everything apart and discovered the wires on the thermal sensor unit on the radiator burned up. After calling Polaris and choking on the 95.00 price I found an aftermarket replacement for 28.00 shipped from Caltric. Several folks on the net have done the same. Anyways I put it in today and still running hot. I can run the fan straight from the battery or if I unplug the sensor and jump the wires on the atv side the fan comes on. Caltric says I need to consult a repair shop. I think the fan normally comes on just by turning the key on then shuts off once you start moving until the engine gets hot. It does not come on now when I turn the key.Is that correct ? Should I have just bought the part from Polaris ? Any ideas ? frustrating. Thanks, Pete