Hoping someone can help with this. 05 Grizz 660. Temp light comes on after 4 or 5 seconds at WOT and only at WOT. Can ride through the mud, creeks and all through trail at fast and slow speeds no light. Hit the straight away and temp light comes on with no normal signs of overheating. Fan works, coolant level OK, oil level OK. Rad is clean, no caked on mud on pipes. Like I said, never actually overheats and light only stays on as long as I am at WOT. Anyone?

 

Did you ever find out what the cause was?