Hi everyone,
I'll be a bit long to explain precisely what happened hoping that someone will help me!

My 1999 Audi A4 headlights range adjustment was not working so I've taken it to a car electrician to fix it. My car's interior lights were working fine till then.

The guy not only didn't fix the problem but when I got the car back, I discovered that my car's interior lights (radio and a/c buttons, etc.) would not be lit when I turned on the headlights. The instruments' lights which are turned on with the ignition and not when the headlights are turned on were still working fine.

I've taken the car back explaining the problem. After 2 hours he called me to go and get my car since it was fixed!!! Unfortunately, it was not! The guy discovered that the problem was occurring because there was no voltage on the headlights range control adjustment switch which would lit that switch (which is supposed to be lit when headlights are turned on). This was causing the circuit to be cut and the rest of the lights that turn on with the headlights not to get voltage too. However, he could not find out why there was no voltage on the particular switch, saying he checked all relays and fuses. As a solution he installed a new wire from the fuse box to that button and the problem was "fixed". The problem with this workaround is that the radio, a/c and other buttons that get lit with the headlights got isolated from the dashboard's dimmer and as a result I cannot dim them.

According to the guy, the only thing he removed for fixing the original headlights adjustment was the switch and then he traced the wire all the way to the headlights to see what was wrong. Can anyone suggest what I should check to make sure that voltage from the original line reaches the headlights adjustment switch? This should solve my problem.