The fan should not be running all the time. It should only run when your car is at operating temp. Its main purpose is to be there for when the air flow(car not moving) is not sufficient to bring the coolant down to the ideal temp. If your cooling fan is not operating you should check the cooling fan itself(hotwire it to see if it runs), the fan relay(under hood fuse box), or the fan switch(located on the thermostat housing, has a two wire connector. to find it, follow the lower radiator hose until you hit the engine block.) These are the most common problem areas...the only other place to check is the wiring to these parts. The A/C fan does serves the same purpose but for the A/C condensor. Both fans usually turn on when the A/C is in use.