i just replaced my t-stat because my car had been overheating to redzone after 10 mins of running regardless of moving or not. i tested the old one in boiling water and it did not open indicating failure.


once i got the new one in and supposedly got any air bubbles out of the coolant and topped it off i let the car idle. after about 15 mins, it began to over heat. it went up just next to redline for about 1 minute then went back down to normal.


all this time the fans never once came on. so i turned the AC on and both fans came on and i was able to drive for 15 mins or so staying at normal temp. (going to drive more tonight to see how it does)

this tells me there is some kind of fan switch thats gone bad. could anyone tell me where its located and how i can fix this as soon as possible? thanks, i searched.

 

there are 2 fan switches. One is located where the thermostat housing is, and I believe the other one is where the top radiator hose meets the engine block.