Well- I think I may have found the problem. There are two wires coming from in front of the fan, evidently one got snagged by the fan blades, and snapped. So I traced it back to it's source, and spliced it together. That helped some, I also went ahead and installed what I have come to call "dumbo ears" to scoop more air into the engine compartment. We went ahead and cleaned the raditor out with the air hose- with all that done- light only came on once.
It gets up to 220 up hills but cools right off to 180-190 on the way down-
Here is the "doo-hicky" with the snapped wire
So is this the sending unit Tells the fan to kick in, or what does it do?