engine fan switch?

On a '97 Cavalier, is the electric engine fan activated by some sort of a temperature switch, either located in a water passage or sensing the air temperature coming across the radiator? In heavy traffic, at 105F my temp gage will slightly exceed 195 degrees, and the fan will not activate. I have also had the fan activate in 40F driving with the temp gage at 180 degrees. The motor has a 180 degree t-stat installed. I know the fan works, I'm just puzzled as to why it never seems to operate consistently. Any thoughts would be appreciated.
Thanks,

On a '97 Cavalier, is the electric engine fan activated by some sort of a temperature switch, either located in a water passage or sensing the air temperature coming across the radiator? In heavy traffic, at 105F my temp gage will slightly exceed 195 degrees, and the fan will not activate. I have also had the fan activate in 40F driving with the temp gage at 180 degrees. The motor has a 180 degree t-stat installed. I know the fan works, I'm just puzzled as to why it never seems to operate consistently. Any thoughts would be appreciated.
Thanks,

ok first all cavys have the temperature sensor to activate over 195 f

if u installed a 180f thermostat the fan will still comming on at over 195

because the sensor kicks in at about 205 f thats when ur cooling fan turns on

it is normal in all cavys if it passes 205 f and not turn on then have it checked

is easy to see it is when it passes the middle line on the gauge

u will see it comming down again thats when is normal