First of all, welcome vmar. Kiev, huh? I've always liked their chicken.
Just kidding. Happy to have you aboard. You've made the "SVX World Network" even more global than it has been.
As for your climate control problem. Where does this "tube" run from. Is it at the "sensor" on the dash? I'll have a look at my service manuals tonight and try to chase your problem down. Is this just a "clear tube" or are their actual electrical connectors associated with it. Just trying to get as much info as possible, so that when I see the "tube" I'll be able to identify it in a diagram. If the diagram is not too "disjointed" or flows across a couple of pages, I may just scan it and e-mail it to you.
Anyway, we'll figure it out somehow. You may try posting this in "eddycat's garage." "Eddy" is a Subaru Senior Master Technician and may be able to give you an immediate answer. And, don't mind his "brash" demeanor. He's basically "harmless."