Does any1 know at what temp the "high temp" light comes on at? Is it close to blowing, or is it set at a pretty safe temp and just there to "scare" you? I've had mine come on, on the Explorer 500, a couple of times, after the radiator was clogged with some nasty/soupy mud, but it never over heated. I'm sure that there is a "comfort zone" built into the sensor, but what temp is it at?
Later,

 

OK, since you asked ...

The coolant sensor turns the fan on at 180F and off at 149F.

The High Temp Light comes on at 221F. How close is this to critical (engine damaging) temperature? Good question!!

Is the coolant boiling point necessarily the point where engine damage occurs? One person in our riding group plugged the rad with snow while blasting through deep powder. The machine boiled all over. It was shut down quickly, allowed to cool, then refilled. Many miles later and apparently no harm done.

DJ