I was replacing my alternator and didnt notice that the nut was attatched to the wiring harness. It spun and broke a sensor that was connected to the thermostat housing. I dont know what the sensor is. Its not my temp sensor because the gauge works. What does it do and where can I get another one?

 

This is the coolant temperature sensor for your ECU. (Yes, you do need it). The gauge is driven from a sensor directly below the oil pressure guage on the drivers side rear of the engine, below the oil filter.

You can get a new one at any fine parts store (NAPA, CarQuest, Advance, Autozone, etc.)

 

thats what I thought. Probably why I was having rough starts and low idle.