I'll check the hoses later today when it warms up outside a bit.

What do you make of the loss of defrosting ability? I had an old car that did the same thing, and it ended up being the heater core. It's almost as if the condensation on the windshield is more than just water (somewhat slimey when I try to wipe it off).

I'm trying to tackle this ASAP because I don't want to be stuck with absolutely no heat in the freezing cold. Also, the condensation on the windshield is bad enough that I have to wipe as I'm driving... not safe.