The cooling fan on my 04 Sportsman 600 has been acting up lately. For the past week, it would run all the time when the key was turned on. Yesterday, the fan quit working and the engine overheated(coolant was bubbling). I tested the fan and it is definitely working fine. Where is the sensor that tells the fan when to turn on? There is one on the cylinder near the thermostat, and there's one on the bottom of the radiator. Which one is it? Thanks.

 

On my 500ho it is on the left side of the engine. If you unplug it the fan should cut on. (2 wire plug)

 

That engine sensor works the overheat light the one you want is locted on rad #25 it tell the fan when to turn on or off .

 

I don't have that on my 500ho. I just have the one on the engine and it does tell the fan when to come on. I see that mine is called the Thermo sensor. I did however know that some models had a sensor on the radiator because people hook up temp gauges there and I wanted to do mine but I don't have one.

 

I just looked it up myself and TLC is correct. Number 25. It to is called the Thermo sensor.

 

Thanks everybody. It turns out that the thermo sensor on the radiator had a broken wire. I replaced that sensor, and the fan is working normally now. Part number was 4010161, and it was on back order from Polaris. Had to call about 10 dealerships before I found one!

 

You can get them from the parts house, Wells # sw 526, may have to change the ends on the wires. Mine cost like $30.00

 

I just notice that, The 05 do not have a rad sensor anylonger, I guess the sensor on the motor works both the overheat light and fan now.

 

That's great info to know! The OEM sensor from Polaris was $70. I didn't have a choice though since I'm going trail riding tomorrow.

 

Make sure you check the plastic radiator neck and the cap. When mine overheated from the sensor going bad, it warped the neck and I did not get a really good seal and it leaked. I had to replace the filler neck and the cap. Not something you want to find out on the trail.