Hi all.

I have an audi b5 2001 tdi 85kw with a lighting problem.

My dashboard light suddenly went out. After some inspection, all the lights in the interior that can dim are dimmed to almost off. Yet the dimmer switch in dash works fine for the light at the clock and odometer.
Both rear lights and both front city/parking lights (the tiny ones) are off.
There is no power to fuse 22 and 23.
The buzzer for remembering lights and the green light in the dash do not work either. blue light for high beam, etc in dash work like normal though.
When car is off without key and the light is still turned on, only the licenseplate lights work.

This car has the strange lightswitch handle next to the index handle.

For the rest, the car has no issues starting or whatever.
I drive around with the fog light as backlight now. Not ideal!

Does anyone have any idea? Or how to test the handle? Where can I find the cable coming from it?
What to do?