If you unplug the wires going to the fan it will automatically turn on the 'HOT' light.You may have a bad connection on the power or a bad ground.

 

I would replace and reinstall the thermostat. Without it the coolant is constantly circulating without having a chance to cool down from airflow through the radiator. The thermostat stops the water flow through the radiator, allowing the airflow through the fins to cool it, until the water in the engine gets hot enough to open the thermostat, allowing the water pump to pump the hot engine water out; and the cooler water in.

 

I have a new thermostat that I will install at the same time as the new engine temp sensor, when I get it from my dealer. I sure hope this does it cuz the only thing left might be a bad ECM. UGH!

 

<div class="FTQUOTE"><begin quote>Originally posted by: RickCJ7

Get a new temp sensor or unplug it so the fan will run. Quit overheating your engine before you ruin it!</end quote></div>

Hey, also, just FYI...If you unplug the fan from the engine temp sensor and try to start the machine it will not run. ECM will cut off fuel as a safeguard to keep you from blowing your machine up. There goes that by-pass idea.

 

Yes the ECM,I forgot about those,pretty well everything electrical has to run thought that weak link.

 

Yeah, and I have read on other forums that the quadivator "fan on switch" retrofit I have been considering might not work on my machine due to the ECM. The ECM is looking for a certain resistance from the fan/temp sensor combo which sends a message to a relay that controls the fan. A fan override switch gives the ECM false readings and may cause other problems. Just try to run a mac program on a windows machine!!