My 2003 Caddy has an AC problem. HELP! :)

I think it's the blower motor, but here's what it's doing: When I turn on the AC (or vent or heat) sometimes it works perfectly, sometimes the air doesn't blow at all but the compressor is turning on under the hood. After a few minutes the air will start to blow and it may or may not stop. The rear air always works perfectly. Thoughts?

I think its the vents inside the dash that broke and are doing what they want and directing the air wherever it wants to go. When you put it full blast, can you hear the air?

Blend door sticking?

Silver.....yes sometimes.
Red.....don't know, but that would suck!