I have a 2001 polaris sportsman 500 H.O. I have replaced the fan and the thermial fan switch,and checked the thermostat. Everything is either new or works there are no bubles in the coolant when its running I am running out of opptions . If I unplug the thermal fan switch and plug a jumper wire in the fan will run. I thought the new switch was bad and I tested it and it is good

 

if you can jump across the terminal and fan runs that is good. now you said you checked the new switch and it is good. but think about it this way the switch is open when cool closed when hot therefore fan runs. so why doesnt your fan run if the switch is good? try another switch and or put switch in water and heat it with a thermometer and see what temp it closes at....

 

If all else fails run your own switch,Use a relay and u could go to auto parts store and get automatic switch,U put sensor in fins on radiator and it turns fan on.Or just put lighted switch on somewhere. I say lighted switch cause u get a visual reminder fan is on

 

the switch dose close at 194 ,195 .i did check that.any other ideas please. and i would real like to fix it the right way if possible. thankyou both for your suggestion.

 

I had fan issues with one of my SP 450/2006 ......I know on my quads the ECM controls the fan..........................Not sure about yours..............do you have any wiring diagrams for the ATV?
....................Caper..........

 

Check for fuseable links in wires. I'm not sure how your wiring is but if u can get wires that run to fan try and trace to where they start. and put power into wires and see if they make fan run from where u are at start at thermostat sensor. I'm thinking a ground is bad. If u get in water lots can make ground contact rust and bad. just ideas

 

do a search for the recall on the emc. i think some of the 04.5 were part of the recall for the emc recall. does it overheat becasue of the fan not coming on?

 

my sportsman is an 01 500 ho. it dosent have a fuseable links it has circut breakers. i replaced it while replacing everything else. i was goning to make a ground for it and try that. thaks again and keep the sugestions coming

 

sorry harley i was thinking of wrong post.

 

harley, I would try a new radiator cap. If your cap is bad your engine will appear to overheat before the fan turns on at 195 deg.