I can't figure this out for the life of me, but my blower motor box leaks water every time I use my AC. The more I use it, the more it leaks, sometimes even gushing out. Does anyone have any ideas for why this happens?

 

you probably have a clog in one of your lines and its creating a lot of condensation. i would take it somewhere and have them blow the lines out. it has happened to me before

 

roughly how involved is this, and how much does it cost especially since my ac isn't retrofitted yet?

 

The drain hose is probably plugged. There is a hose from the back of the heater box that drains the condensation out under the car. If you blow some air into it from under the car it will usually break the blockage loose.

 

All manufacturers incorporate drains in the bottom of the evaporator cases just for this reason; as the air passes thru your a/c evaporator (and cools) the air can no longer hold the humidity (water vapor) in suspension, and it collects (and drips) off the eveaporator core. The drain is there so as to allow this collected water to drain out of the case.
On extreamly humid days it's not uncommon for a cool mist to exit the dash vents when the fan is on high from time to time.
The time to become concerned is when you see this mist all the time, or you see cold water leaking into the passenger compartment at the passengers' feet. That indicates the case drain has clogged (water can't get out) and has to be cleaned out.

P

 

look under the car on the passanger side u will see a small hose that hangs down. u can take metal coat hanger and shoce it up there to get the blockage free. but watch out u might get wet.....lots of water is probably all blocked up back there

 

take car to a shop and have them blow compressed air in the a/c drain hose ...but it is not a permanent fix cause whatever is in the evap will ventually plug it up again ........

permanent and proper fix you need to remove evap and clean all the debris that is trapped in there