What could cause your 500 sportsman to over heat?

I suspect is is overheating for the same reason mine is. The coolant temperature sensor is bad. I jumped to gap between the terminals on mine for a second, and my fan started running. I haven't heard the fan on mine running in quite a while. I don't like to throw parts at machines, especially at other people's expense, but if your fan doesn't work, it would overheat.