Q: Overheats at idle, too cool while driving.

The radiator fans only seem to kick on low when I turn on the A/C. Only kick on high when I disconnect the Cylinder Head Temp. Sensor. SOOO I know both speeds Physically work. (Two fans, both spin freely.) Also have checked, (with my ears and with feel) that both associated relays work, or at least make a click.

I've let the car idle up to temp, and neither low nor high speed seem to turn on. I've let it idle up to about 240F before I get scared and turn the a/c on to cool it manually. (just about boiling over by this point).

Another wierd thing, is that when driving consistently (i.e. Freeway), the car runs Cooler than normal.(Needle physically moves more toward cool on its own.) Temp is anywhere from 160f - 190f during that time. Before issues, its normal was like 210f.

I have Replaced: CHTS, Fan resistor and pig tail, (part that susposedly operates low speed), Thermostat and its housing. Coolant is in good shape and alwyas topped off.

Regards, Josh S.

My car has 160500 miles.
My car has an automatic transmission.