And when should it be on? I started the car and looked under the engine but the fan wasn't turning. How do I know it is working?

 

Power steering fan. Not sure of the duty cycle, but no, it isn't always on. It might turn on with the radiator fan - at least it did in the early '02-'03 cars. With the car off you can spin it to make sure it's not seized - some also unbolt it and turn it over to clean out the gunk that accumulates on it.

 

Youll hear a high pitched whine when the wheels are straight.

 

ok i found in another thread that it turns on when the AC is on so I turned on the AC and the fan started spinning so all is good. Thanks.