I have a 2006 yamaha grizzly 660.
I notice that the cooling fan always comes on and stays on once I ride for a bit or it sits idling for a few minutes.
The temp light doesn't come on when this happens.
Yesterday I started it up. The outside temp was around -17 degrees celcius and I just let it idle for about 10 minutes and the cooling fan came on.
You think with it being that cold that the fan shouldn't have to come on.
The rad is not blocked.
Is this normal or is there a cooling problem with the atv?

 

its normal.
my grizzly does the same thing.
the only time my temp light comes on is when i let it idle in warm weather or if i ride hard in four wheel drive.
but your fan is supposed to b cumming on just about all the time to keep your motor at a certain temprature.

 

Don't worry about it. They tend to come on fairly quickly when at idle(in any temp) due to low coolant/air flow. Just make sure you're topped off on oil and coolant. As long as the light stays off you're good to go!