Ok, well me and a few mechs are confused on what is going on here. My fans do not click on, even when heater is all the way up. I just replaced the thermostat and the fan switch that is connected to the thermostat, i drained my coolent and replaced fluid, i squeezed out all the air bubbles. all connections seem to be fine. and after about 10 mins of driving it will overheat, idle is fine, doesnt ever overheat during an idle, and last time i drove, the temp guage would change from normal to high and back down rapibdly towards the end of the driving session, i unpluged the hose that connects to the intake to check and see if my head gasket is gone, i didnt see any white smoke what so ever, so please help me out a little here, give me some insight on what to do or look for. im stumped...