HVAC Issue VX Acclaim

[Scruba]

Hi all.

I replaced the dials behind the HVAC today and took the chance to have a look at the hissing coming from behind it when the direction selector is at feet only. I wiggled the tubes around and found that if pushed to the right of the dash it goes away but returns once they come back to centre. When the hissing is there air only comes out the windscreen vent. Over time after driving and a little wiggling of the switch (selector) the noise dissapears and the feet only vents work.

Any ideas to make this dissapear for good and is this a common problem?

[Scruba]

Anyone have any idea?