A/C Sounds like its blowing but no air flow

[jizay]

On a trip recently my automatic A/C (its the one that has seperate temp control for driver and passenger) seemed to work fine. Then it seemed to just blowing air out of the front vents. I switched to all the different vents and could barely feel anything. I turned the fan to max and it sounded like it was blowing hard, was very loud but nothing was coming out of any vents. Almost like a door was shut keeping the flow from getting to the vents. Eventually I turned the a/c button (snowflake) off and it got quiet even though the fan was on max. when i hit the button again, loud as can be. At one point I just opened the sunroof, left the a/c button off, fan still on and turned the a/c mode to outside air (not recirc). This had some air flow coming through, eventually I hit the A/C button again and there was no loud sound and the air got cool. Anyone have an idea? Would this be the final stage resistor?

Thanks.