Windscreen demister not working

[thenamesdaryl]

Firstly, i've searched and searched and all i can find on this topic is information on the old design with 3 visible motors/flaps, i seem to have something different!

I have a 2008 A3 s-line quattro 3dr, every part of the climate control works except the windscreen vents/demister. i've had the glovebox out and can see some moving parts, however i am not sure what to be looking at really. the only thing that moves is the recirc flap and white cog right up the top, this moves when i select the feet / middle vents, but does nothing when i press windscreen.

There is also a yellow level i can see tucked at the back at the bottom, this doesn't move at all... i had the car read on vagcom for another issue, and noticed a code for demister flap but didn't pay too much attention to it at the time.

can anyone help?

 

[thenamesdaryl]

just annotated 2 of the pics just to be clearer

 

[SootySport]

As the flap motor works it does seem to be diverting air as it should.
Does the heater fan and led by switch work? and have you changed pollen filter or at least checked it is not blocked?

 

[thenamesdaryl]

Is the only moving part the white cog? It does looks like it should rotate when i press the switch to a new position. The led lights up, no noises or movements at all when pressed. The heater fan works fine, to be honest i havent checked the filter, i figured it would be in the system before it reaches and outlet, ie the feet and face blowers aswell not just the windscreen, or am i wrong?

 

[SootySport]

I'll be having my glovebox out next week, I'll check which bits move with the screen demister on, let you know. In the meantime no harm in checking your pollen filter.

 

[thenamesdaryl]

ok that would be appreciated, ill have a look at the filter, thanks

 

[thenamesdaryl]

anyone got any more hints/tips? still struggling with this!

 

[SootySport]

Sorry, not had a chance to get in there yet.

 

[hollows wife]

theres also the electric heater thats built in to the airbox , maybe thats burnt out , maybe not , try it on auto setting . also you can do a basic setting on the airflaps with vcds to re-align them all

 

[SootySport]

Had a look today. When you press the windscreen demist button, the large white cog you mention turns about 90deg. clockwise (as you view it from the passenger footwell) and the fan speeds up. That's all that seems to happen.

 

[thenamesdaryl]

thanks for that soot1, when i press the button it looks like the white cog tries to turn but doesnt actually move, i suspect the vent flap may be stuck. i will have to do some further investigation!

 

[Mitchme87]

thanks for that soot1, when i press the button it looks like the white cog tries to turn but doesnt actually move, i suspect the vent flap may be stuck. i will have to do some further investigation!

Hi, did you find a solution to this as I have the same problem. Had the glovebox off last week and disconected the wire that runs the white cog and seemed to reset the position but low and behold a couple of days later when it had snowed and needed it to work it decided to not again. All other vents working fine.

 

[ch1z64]

Might be worth having a look at the Q3 Climate control the adapation part as i would think the test will tell you if all is working using Vcd's plus have your CC on . It's worth a try nothing to lose lots to gain

 

[Mitchme87]

How do I do this?

 

[ch1z64]

Yeah goto 08 HVAC then 04 Basic settings, Group 1n 2 then click on/off and wait until it says Adaption OK, that did it for me.
I found that if the CC was on you will be able to hear and feel air but it might not be any help with demister but nothing to lose trying it

 

[Mitchme87]

What are you doing this test on?

 

[ch1z64]

What are you doing this test on?

You would be testing your vents to see they are all working but as you have a demister problem it might not help you as i said earlier

 

[Mitchme87]

Do you know which colour arm moves the demister flap? 2008 model

 

[ch1z64]

Do you know which colour arm moves the demister flap? 2008 model

Once i fitted my Q3 CC into my car S3 i run through an adaptation and after i did it my Cc worked fine meaning all flaps opened so allowing air through . So it might just be worth a try