I'm suspecting the new sensor is defective-when we had the initial problem, we checked all the wiring,cleaned all the connections,and took out the sensor and boiled it-and found it wasn't working.When we put the new one in,everything worked fine-up until a week ago, when it overheated without the fan coming on.Then it worked fine for a few days[probably not more than a couple of hours max,] and the same thing-the fan didn't kick in,which normally starts running after 15 or 20 minutes
At $90,I would think the dealer would replace it,but I'm not holding my breath....but the total running time since it was replaced has to be well under 10 hours.
i know a lot of people dump onn Polaris-but I really like this quad[2004 sportsman 600 ],its been lightly used and runs well-except for this one problem.I'm thinking of installing an overide switch-the last thing I need is to be stuck in the bush miles from camp with moose quarters and the quad overheating.