Dead gauges
 

I have a C220D '96 and I have the following problems:

1) The gauges (counters) doesn't work, not any, the speedometer not, the fuelmeter not, the temperaturemeter not.

A time ago they worked only sometimes fine, but now they are completely dead. I chekked the fuses, they seemd to be good. I tried another clockunit, from an one year older car, and the clock didn't work. What can be the problem?

2) I think that my engine goes very hot when I drive a while on the highway, I can't see how hot ofcourse , because of my defect clockunit, but after driving a long distance, the power decreaes.
maybe the thermostat?

Can somebody give me a good advise??

Check you have a good ground on the console, if the dash lights do not work as well that would confirm the cause; your ground has failed.

I am sorry, but how do I check that? I already checked all the cables behind the clockunit , but I didn't saw anything that wasn't good. How can I check the ground if it is good?

Nobody with the same problem??

That is not possible.

Fuses?
 

Take a close look at your fuses. The inside of the fuse cover will tell you which ones affect what system. The fuses tend to get brittle with age and will cause such problems