OK, so I have a Fabia 1.9tdi (2001). I bought it second hand and I'm discovering a fair few nigggles as I get to know the car (lesson learnt!). I've asked the forum about a 'worrying knocking noise' but don't want to overload the forum with a huge list of the issues I need to resolve.

One problem that has to be resolved is that of the vents.

At the moment turning on the vents (1-4) blows air through the passenger foot well on all vent settings (dash, windscreen etc.). If I select the windscreen vent air does not come out the windscreen vent and selecting the dash setting does not give air through the dash. Only when I select dash/windscreen do I get air from the dash vents (but still nothing from the windscreen vents).

One other thing, the A/C switch has no effect - no idea if this is relevant.

My big issue here is that my windscreen is very misty in the morning and it's virtually impossible to clear.

Can anyone help?

(Until I get this fixed, any ideas on how I can stop it misting so badly overnight/clear quickly with the vents?)

are other windows misty, if they are along with the windscreen could be leaky doors,

sounds like a vents selector switch has died,

From the sound of things you've got 2 separate issues here:-

1) Vent controller stuck or dead. Get fault codes read to confirm this, and identify which one.

2) I think you may have a problem with the air con gas level or compressor. Take the car to an automotive air con specialist for this if it's not under a used car warranty. If it is, and air con's not covered, or parts failure is but "consumables" aren't, take it to the a/c specialist anyway.

The vent kn0b is a direct cable connection to the heater unit, and is I believe a bit of a pig to reconnect/replace. As it's purely mechanical I'm not sure it would show on VAG COM, but someone like Lummox may know better.