The red battery indicator light on my dash just came on. The last few weeks when I cranked the car up I heard a fan kick on for about 5 min, making a high pitched noise. Once the car is in park it seems to idle high and that fan (or what ever it is) can be heard, but not as high. Now the radio will not even come on, it is almost like something is draining my battery. What could this be????

Thanks