Climate control, fan, vacuum stuck on windscreen

[CJ_Calais]

Hey everyone I've got a l67 vt Calais with the dual climate control and the mode button(selects like face, feet, windscreen) is permanently stuck on windscreen. The display reads that it's changing position but it's constantly on the windscreen. I've found a hose that was perished and is since broken that leads into the firewall through another very perished rubber type door/skin (heater hoses go in it as well). I'm assuming this is the problem except that the windscreen still works, which confuses me. Also that when I press mode I can hear the air changing(or at least trying to change) direction, but it's still on the windscreen. Is this the problem? And how would I go about fixing the perish door thingy and hose, when I can't see where the hose actually goes after the firewall?
Help would be much appreciated as I'm 16 and don't want to spend any unecessary money on it!

 

[accentstencil]

Replace the perished hose. I think you will find that the vacuum hose goes through the firewall and connects at the rear of the intake manifold. When there is no vacuum the vent position defaults to the windscreen.