Defroster tubing full of water

[bob109]

Just completed my trek from Pa. to Fl. Having encountered temp/humidity changes through several states I had to use the front windshield defrosters on several occasion. I encountered a preplexing problem with the driver side defroster discharge vent. Absolutely no air flow could be felt. Had plenty air flow on the passanger side front window. Upon arival in Fl. I opened the front access panel on my Discovery. I was rather amazed on what I found. The flexable rubber tubing for the driver side defroster was filled with water and had completely blocked any air flow through the tubing. I inserted a large hollow basting needle through the lowest portion of the tube and drained almost 1/2 quart of water from the tubing The tubing was draped down and acted as a "sink trap". The water must have collected over time. I'm at a loss as to where the water came from or how it entered the tubing.

Has anyone encountered a problem of this nature?

[gaugeguy]

That's just plain weird.
If you have an engine-powered automotive-type AC unit in your driving compartment the evaporator (inside) unit can produce water if the coils freeze up. They even produce water when they don't freeze. A coil freeze-up can actually hold a significant amount of water. When the coils defrost (which they do when not in use) the melted ice usually drains out a hole in bottom of the evaporator housing to the outside.
Possibly the drain hole is plugged and the water blows into your duct work when you turn on the fan?
If that's the case then why is there not more duct work showing water? I don't know.
Ever seen water from your family car AC puddling in your drive way after you stop? The moisture has to go somewhere.
Might have an AC guy check it out.

[wa8yxm]

I see 3 possible issues.

The defroster normally runs the air conditioner (To dry the air) as well as the heater if you choose to add heat... As the other responder suggested.. Clogged drain.

Depending on the placement of the defroster vents... Leaking windshield seal.

Blown heater core