problem with window condensation

hai, i'm the owner of a lancia zeta. its the same as an ullysse
we are happy withe car, except one thing.
in the winter when the front window is condensating, we cannot get it clean
it looks like the front opening isnt giving hot air.
when i push the button with the window-sign on it, the light goes on.
whenb i push the buttons for the fan, to increase speed, the window light goes off....
is there an electric valve which doesnt open? can i get to this valve?

please help.

tia patrick

Is the 'recirculation' button selected?

Make sure the air conditioning compressor is on, it will remove the moisture

tried the recirculation button, same affect.(no effect)
the airco has to be filled because i had a leak.i replaced the broken hose but not filled yet.
but shouldnt it work without the airco?

anybody knows how to get to the ventilation system? just a hint please so i dont tear the car completely up.

tia
many thanks for your quick replys