On my 99 SLK, the console cigarette lighter does not work. At first I thought it was the things I was plugging in (chargers, etc), then I checked the fuses (they're all ok), so it must be something else. The lighter itself does not work either, but I never noticed before since I do not smoke.
I'm thinking it might be a loose wire. Is there any way to access the back side of the lighter to check for loose connections?
To remove the console for access on a manual shift car, you pry off the shift boot and then the trim piece that surrounds it. (Doing this from memory. I think the automatic is similar.) That will expose a couple of screws that need to be removed. Next open the console storage lid and look for a flap in the bottom liner at the back - this is very difficult to see. That will expose two nuts that need to be removed.