I agree, please don't use all caps!!!
I must agree with Suginami, it is both offensive and harder to read your post with all caps. On to the problem - You might have a poor ground to the dash causing your problems (Mercedes vehicles are notorious for poor solder joints most everywhere on their wiring and printed circuits). This could be the result of a cold solder joint on the printed circuit board on the panel itself, or could be in the wiring from the plug to the ground.
You can easily check this by connecting a multimeter between the ground circuit of the panel and a true body ground somewhere on the sheetmetal of the body. If you measure any voltage between these points, you have isolated your problem to a poor ground circuit to the panel. From there it's just a matter of locating the failure point and correcting the problem. If it turns out to be a cold solder joint, try to remove the old solder first by "wicking" it off the panel, then apply fresh 60/40 rosin core solder. It might also be a good idea to check the integrity of the ground strap from the engine to the chassis.
Good luck chasing it down!