When I turn on my AC, its blowing cold air, but you know its quiet when the AC is blowing at full speed. But now lately, when I turn the knob to the max, I hear like a fan noise. Its noticeable/little bit loud, sounds like its coming from the passenger side underdash. Any info on this? But when I turn the knob in a meduim postion, it gets louder comparing it to when its to the max. Any info?! Thanks!