A/C drain clogged

So... After a 3-day trip up to Yorktown and back (4 hrs each way) and heavy use of the A/C, I have water on the PS floorboard and obviously a clogged A/C drain. This morning I tried shoving a piece of plastic trimmer string up through the drain in front of the firewall on the PS side but didn't get very far with the string and no release of water.

So, I went in under the dash and found a flexible tube that comes off the bottom side of the blower motor that appears to go up to the drain tube that comes through the firewall.



However, this doesn't make sense since it is lower than the firewall drain, not higher, so I don't understand what this flexible tube is for. It doesn't show up in my FSM, nor does it show the drain tube coming through the firewall so I can't trace it back.

So, I guess two questions:

1) What is the flexible hose in the pic above?
2) How do I unclog my A/C drain?

Steve

So I went back out this afternoon, blew compressed air into the tube coming out of the PS firewall below the battery, and it now seems to be draining properly. I took the PS seat out and pulled up the carpet... LOTS of water under there so I'm going to leave it up and let it dry out for a few days...