Welcome!
First, unless you are across the pond, around here a Merc is a Mercury. You have a Mercedes, a Benz, a Mercedes Benz .........
Second, on your key board, down under the "K" and "L" are punctuation marks, like the comma and period [, .] They are your friend, and more importantly, for anyone reading your post they are their friends.
The climate control buttons have a type of fiber optic cable behind the dash that plugs into the buttons. There is a main bulb in the dash that provides this light. Do your dash lights work?[instrument cluster] If they don't work either then search "rheostat". You will find how to solder it.
What is your location?
Again, welcome!