I have a 2001 Mercedes C320 and this has happened to me twice within the last two months. While driving, all of a sudden the lights on dash go out, including speedometer, odometer, gas gauge looks to be empty, heater/A/C off - the engine still running & the radio still working. I don’t know about the headlights because it was during the day & I didn’t think to check. Both times it was after 5:00 or on the weekend and my mechanic was closed. Next day after starting the car everything worked again. Any ideas what could cause this?
First guess would be a ground wire. Freshen up the connections and make sure the ground from the body to the engine is intact.
My first suspect would be the power connection to the dash or cluster has a bad connection to it. The trouble could be inside it also.