2002 BMW 540I air/conditioner not blowing air at all.

Hello, This beauty is is sadly killing me softly. Driving down the freeway and the AC and air stops blowing. No air. I pushed all different kinds of combinations of AUTO/RECYCLE and cannot get air to blow out. I replaced the cabin air filters just to make sure they were clean but now the air will work on and then turn off when it feels like. I can turn on the car and it will work, then if I turn off the car and get back in from work the ac/air bill not blow out. I can hear something turn on when I turn on the fan and ac buttons but nothing blows out. Then some days it will work like a charm cold and strong. Any ideas?