Audi A4 B6 1.9 Tdi - Windscreen de mister nor working | Technical matters | Back Room Forum

News
Reviews
Real MPG
- Find your Real MPG
- Best MPG Cars for 2025
Ask HJ
- See All Ask HJ Questions
Advice
Free Car Valuation
- Get a FREE Valuation
- How To Sell Your Car
Cars For Sale
Profile
Log out
Log in
New account

Sat 29 Dec 2018 17:13

Audi A4 B6 1.9 Tdi - Windscreen de mister nor working - Steveieb

Utter nightmare since returning from holiday I've noticed that the windscreen de mister fails to direct warm air on to the windscreen.
Took the glove box out and lo and behold the lever mechanism looked as it it was working.

So prematurely I refitted the glove box only to find the de mister not working.

I have tried contact cleaner on the connection and WD on the joints of the operating arms which are now locked solid.
I've ordered a new motor and my plan is to plug it in to see if it works as the linkage looks complex or is it ?

Please can you hel p ?

Reply | Report as offensive | Link

Sat 29 Dec 2018 18:36

Audi A4 B6 1.9 Tdi - Windscreen de mister nor working - llos

There is no easy answer to this problem the flaps on the demister become worn and stop working the answer is to remove the heating mechanism no easy job.I have never done this job but my son has in his workshop it took two days solid work apparently.U hope it is something else.

Reply | Report as offensive | Link

Sat 29 Dec 2018 19:19

Audi A4 B6 1.9 Tdi - Windscreen de mister nor working - Steveieb

Thanks Ilios

Woul write the car off.
I'm hoping that coupling up another motor will prove whether it is motor failure.
The whole mechanism has seized up yet yesterday it was free. Sounds like the flaps jam

Reply | Report as offensive | Link

Sat 29 Dec 2018 20:01

Audi A4 B6 1.9 Tdi - Windscreen de mister nor working - Steveieb

Is it possible to free up the flap by jiggling it

Reply | Report as offensive | Link

Sat 29 Dec 2018 20:59

Audi A4 B6 1.9 Tdi - Windscreen de mister nor working - elekie&a/c doctor

Are you sure you are looking at the correct flap mechanism?Remove the servo motor ( 3 screws) and operate the flap by hand . All the servo motors are the same electrically, so they can be swapped out for testing. Just take a photo of their position on the heater box before removing, so that they can be refitted in the correct rotational position

Reply | Report as offensive | Link

Sun 30 Dec 2018 09:20

Audi A4 B6 1.9 Tdi - Windscreen de mister nor working - Steveieb

Many thanks Elekie Doc.
I'm sure I have identified the correct flap as the demister mechanism is colour coded green. It is operated by pressing the windscreen demister button which lifts the flap.

It started working when I removed the glove box. And worked ok for a couple of days. But when I replaced the glove box I found it was not working again and under examination I found it had seized up.

Is it difficult time relocate the motor onto the operating arm ?

Or would jiggling the mechanism help to free it up ? I've tried WD.

Cheers

Reply | Report as offensive | Link

Sun 30 Dec 2018 15:12

Audi A4 B6 1.9 Tdi - Windscreen de mister nor working - elekie&a/c doctor

Remove the suspect demise servo motor and plug it in to one of the other connectors on the heating unit. This will prove if the motor is at fault . Take a photo of the linkage position before removal. I have never seen a flap seize on one of these yet, unless something has fallen down the vent.

Reply | Report as offensive | Link

Sun 30 Dec 2018 18:51

Audi A4 B6 1.9 Tdi - Windscreen de mister nor working - Steveieb

As usual Elekie Doc, brilliant advice.

I have ordered a replacement motor from eBay and will plug this in before removing the old one.
Bit concerned about getting the motor back in the correct position but will take a photo as you suggest.

Basically will it only be 90 degrees out if your u get it wrong. I'd are there only two ways it can fit ?