Mercedes Benz repair: 1985 300d mercedes, black burn, rheostat

Question
QUESTION: is there and where is the dimmer switch for the intrument cluster on a 300d

ANSWER: it should be the rheostat dimmer it is on left side by clock it turns left or right  it is inbetween temp gauge outside it is a black stem knob if it doesnt your rheostat is shot

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QUESTION: i just fooled with the rheostat dimmer and the instrument cluster lit up momentarily, and now the fuel gauge and temp gauge are pegged all the way. also the turn signal arrows are both on but dimmed.

Answer
I had same problem with my 190e chances are yourcircuit on that side of the cluster is fried you will need to pull the cluster out, pretty simple take out horn and take out steering wheel  take out lower shroud to acess the speedo cable then pull out if you took it apart the cluster you can check you will see black burn marks on your side where the circuit gioes to the fuel guage etc. get a new cluster. but do check bulbs etc in back of cluster and bulbs for blinker switch fool around with rheostat