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??