New to the group,need some help with temp sensors on my 2001 Cavalier. The only way cooling fan comes on is with the AC. I've replaced the sensor on the passenger side of the head. Is there more than one for the gauge and the fans? Any help will be appreciated. Replace thermostat-180 and it still is running over 205.

 

for these models...if the heater core is plugged, the car will run hot and even overheat.
the cooling fan won't come on until probably 225*F

the thermostat starts to open at 180 and probably isn't fully open till to 190

measure the temp of the inlet and outlet hoses of the heater core...if the temps are the same the core is probably clogged. there should be approx 10*f drop when the car is at temp.