Recently I've been having a problem with my AC. Before I had this problem, I noticed a strange rubbing/sliding noise coming from under the dash on the passenger side (right above passenger feet) when I would make a left turn. This would only happen when the AC was on. Now lately after driving for a while with the AC on it cools fine, but it simply stops blowing air, and I hear a continuous flow-noise coming from the same place under the dash.
I felt under there and the black plastic box always gets so much condensation that water leaks onto the floor. Then when I turn my car off, have it off for a while then restart it the AC works fine, but of course after a while it stops blowing air.
I Paid $1400 a year and a half ago to get the complete AC system replaced because the compressor went bad and messed up other stuff, and now I have this problem.

What could the problem be? How much can I expect to pay to repair this? Any help would be appreciated.