the obvious first thing would be to test all fuses for power. use a test light to check all the fuses.

start there

Roy

Hi Roy,
As I explained none of the switches in that dash panel operate what they are supposed to , however the headests do work, I dont have a wiring diagram but would assume there must be a something common to all of those switches, there are something like 70 fuses in the merc and I have checked most for continuity and have not found a damaged fuse yet. I guess the question is what if anything is common to that bank of switches, maybe it has lost an earth but where do I look.
Roger.

first thing i always request is this. if there is a power interruption to a computer, and your car has no less than 12, then that could be a common denominator.

anyway, where i am going is towards a body control module which controls all these functions but a scan tool is required to monitor commands and what is on and off. your benz is a real complicated piece of equipment and without actually being able to monitor these systems, it would be an educated guess. these guesses get real pricy on your car as all module require programming after installation.

as far as a ground, start at the battery cables and clean all connections anywhere you find a ground.

Roy