no air from front screen vents

[andy5468]

my audi a4 1.9tdi(2002) has a problem with the front screen not demisting.
it seems that the heater system works from every vent other than the windscreen and side window vents in the dashboard.
i have pushed the quick clear on the dashboard and i get no air through the vent under the widscreen therefore the screen does not clear.
Any suggestions on what might be the problem as this is causing me some big problems in the current weather?
Also does anyone know what the knobbly button is in the middle of the windscreen vent as it does not seem to have a purpose?

many thanks

[andy5468]

well ive managed to fix this myself in about 20 minutes by reading another thread on this forum.

i removed the glove box(5 screws) which gains access to the heater flap motors and levers , i then gave a gentle push on the top arm which is the windscreen lever and it started to function.

if this happens again i will know where to look.

[Dansk]

I'm so glad of this forum, its now saved me a small fotune, as i fix another problem like the one in this post, after reading about it on here!!

[andy5468]

I totally agree.

i have only been a member for 1 week but already i,ve fixed 2 problems through advice and reading info in these forums.
i will save a fortune in garage bills.

[AutoTDI]

I have a different problem with my screen vents. Plently of air comes out, but most of it is directed towards the passenger side. Nice for the passenger, but I think the driver should have priority, or at least the flow should be better balanced. I wonder if the vents have been optimised for LHD. Is there any way of tweaking the air flow for RHD?

[irishyop]

Same at that guys, my passenger gets head and I get froze!!!!! Any points, u think I should start at the glove box thingy?

[AutoTDI]

I've looked at the workshop manual and it does appear that the nozzle under the facia is designed to direct more flow towards the driver's side. However, this is for LHD. If its the same nozzle for RHD then this might explain the problem. I suppose I could try stopping up some of the vents on the passenger side, but I don't want to risk anything falling into the duct.

[andy5468]

The glove box comes out in about 5 mins and gives access to all the heater motors.
Make sure they are all moving fully to allw full airflow.