’06 sportsman 450 fan issues and more

First off, let me say that I’m a newbie when it comes to ATV repair. I’ve got experience working on stuff, just not these quads

So, I’m carousing craigslist and found a ’06 sportsman 450 for sale. The price sounds good to me. The owner says it needs a radiator fan. Says it’s broken. Says the dash display flashes hot all the time. Said it was just at the dealer for a re-flash which, they completed and found the fan was bad.

I did a little searching. I see a few possible issues.

1. Bad CDI/ECM or whatever you want to call it
2. Bad thermoswitch in the engine fooling the CDI into thinking the engine is hot
3. Bad thermoswitch in radiator not telling the fan to work
4. Bad fan
5. Bad circuit breaker in the fan wiring.

Any other possibilities?

I find it hard to believe a bad fan would make the display flash hot all the time.

I could see the thermoswitch in the engine causing the code. I’m not too familiar with the switch but I’d think a simple test of making/breaking the wires to this switch could be a quick test

I’m open for opinions on how to diagnose the issue.

The owner says he can’t read the mileage ir hrs due to the HOT code flashing on the display. Can we override this quickly to see the mileage?