Can anyone provide some information about the electronics on a Rhino, specifically the temperature sender and overheat light?

I have a 2007 rhino and it over heated while running through sugar sand all day in about 90 degree weather. No surprise.

So, I installed a switch to keep the electric radiator fan on if needed and it appears to have resolved the engine overheating problem.

However, now the overheat light comes on 5 minutes after the engine is started even though the engine is not really hot, confirmed with thermometer.

So I bought a new temperature sensor sending unit, the one mounted on the thermostat housing not the radiator, because I assumed I had cooked the original sensor. Unfortunately, I am still getting the false over heat light. Any suggestions to resolve the false over heat signal are welcome.