I started having a problem with my overflow tank spitting antifreeze out after the machine gets warmed up. It doesn't seem to want to kick the fan on. I have checked the circuit breakers they are good, the radiator is clean and full, the fan runs when I put 12V to it, I don't get the "HOT" on the display however. Kind of at a loss as to where to go next. I did run it long enough I felt that the fan should kick on. Does the sensor at the bottom right corner of the radiator need to be open for the fan to start or is it only a sensor that sends the HOT message to the display?

 

Try jacking up the front end with the wheels off the ground and leave the radiator cap off. Run the engine and add coolant as the radiator level goes down. This is a hard model to bleed because the coolant return line goes back to the remote filler instead of straight to the radiator.May take several times doing this to get all trapped air pockets out. Then you can top off the radiator,replace the cap and fill the remote tank. 2005 models they changed this and was a lot easier to bleed.If the fan doesn't come on it could be that the fan sensor on the radiator has shorted.This is an expensive part and cheaper to get this cheap manual to test and check the cooling system before you buy any parts.2004 Polaris ATP 500 Service Manual PDF Download

 

old polaris tech - I have a question for you about a magnum 425 --- have an email or can a direct message you? Maybe I'll just post it and put your name in the tag line??

 

I'm having the same exact problem. I changed the sensor on the radiator and on the engine. Circuit breaker is good. I purged the system some more but the fan will only come on when jumped. Did you find a solution?

 

No...tried the suggestion but didnt help...I ended up just running a toggle switch to start and stop the fan as needed.

 

I may just leave the jumper in and keep the fan running unless that's gonna create another issue.