Thought I would resurrect this thread as i am having a simlar problem with my 87 190D, and found no solutions in my search.

My CCU lights were out, so I replaced the bulbs, they worked for about a half an hour and went out. Then, later that that same night when I restarted the car, they came back on again for a while and then went out. All the rest of the dash lights work fine. . . . it is a mystery to me

Thanks for any help
George