Front Screen demister not working fully

[Spud312r]

Now we have the cold damp autumn/winter weather, I seem to have a demister issue with the front windscreen on my 2010 q7.
Hit the demist button and some air/heat comes out onto the screen, but not fully, as it takes absolutely ages to partly clear (10-20 mins), even when there is enough visibility, the whole screen never clears - very patchy, even when put back on climate control /auto with a/c on.

Anybody have an idea ? blower motor - vent ducting ??

[zollaf]

you really need to start with a diag scan to see if any faults are recorded. do all the other controls work as they should, i.e. can you direct air where you want and alter the temp ?

[Guest 2]

Might just be the flaps needing re-aligned. VCDS can do this.

[Spud312r]

I'll check full functionality as suggested, manually direct flow/heat etc
It does seem as it maybe the flaps, as i get heat from the top vents and some blower air, but very patchy, even when the screen is 30% clear, its only in small certain areas, and sitting waiting for 10-15 mins before you can think of driving of, dosnt seem right
Also when selecting the demist button, i would have expected the blower to go to max, but it dosnt, you have to manually select he blower and wind it upto max.

[Guest 2]

Also when selecting the demist button, i would have expected the blower to go to max, but it dosnt, you have to manually select he blower and wind it upto max.

Might be something different then, best getting it scanned.

[Spud312r]

Might be something different then, best getting it scanned.

Its booked in with Audi this friday as its still under a extended warranty.
Funnily the service guy stated that he had another Q7 with similiar issues, they had to photograph the front screen/misted up and send to ausi to see if the correct screen had been fitted...