W208 320

Hello. I'm new to this forum and this is my first thread.

I've had a problem with BAS/ESP and ABS lights on my dash board for some time now. The problem show up from time to time. It can go weeks without problems, but it comes back occasionally.
This is what happens: Sometimes when I turn on the main lights (or the fog lights), BAS/ESP, ABS and lamp defective will light up (sometimes also "display defective). The car will also sound weird as it's about to choke or something.
The warning lights will shut off and the engine will sound normal again if I turn off the fog lights or just use my park lights.

What's weird is, when I've had this problem before, the warning lights would shut off if I turned the fog lights ON. I live in Norway and it's very dark here in the winter times, so it's a problem for me to just use my park lights while driving.
I changed my brake switch light last year, and I ordered this part from a genuine Mercedes Benz dealer. I have also changed my battery. I've been to two Mercedes dealers who scanned my car for error codes.
One dealer told me they found a code on the brake booster, and the other found a code for the brake light switch.

I have not found any information about my specific problem online, and I would appreciate any responds.

EDIT: Is it possible that it could be as simple as a failing instrument voltage regulator or alternator?