a quick question on this one. is this fan supposed to be always running? oh well, i think my question should be, how does it work?

 

The fan always turns a bit.The amount of slippage is determined by the air temperature from the rad.The fan has a metalic strip on the front which expands and contracts according to the temperature.Regardless of temperature it always slips at high rpm(above crank speed of ~3500rpm)

 

I think my fan is broken, and the other one i got at the wreckers is broken too. It doesnt turn on at any time except for about 45 seconds after i start the car cold. I can tell its on cause it makes a fair bit of noise and air blows from under the car. In traffic when the car is heating up, the fan doesnt work.