Well, my fan never comes on but I run at pretty high speeds most of the time. I only found out it was good when I let it idle for 13-15minutes. And even when it came on it only stayed on for less than 30 seconds. Strange, but I have not had any "overheating" problems nor have I heard of any.
What are your symptoms?
TRX450R...Pulse Charger, 12.25 HH, HotCam S2, KW valves and springs, P&P, UNI filter, airbox outterwears, Woodward fuel screw, Denton stabilizer,ProArmor K/S, Elka Elite longtravel 17" w/dual linkage, Figair airbrushed hood, Holeshot fronts, Razr II's rears, AC Propeg nerfs, +1 1/2 stem, Armidillo skids.
And a very well modded 03 warrior, engine, suspension, etc