I have an '83 300sd that the dashboard lights do not work on. I recently got the car so I am pretty new to these cars. But I pulled the instrument cluster, checked continuity across the bulb and got continuity, the filament looked good, I did not check resistance though, but I am assuming that I have good bulbs. The turn signal indicator bulbs work, and everything else seems to work, but not the backlights.

Is there a switch or dimmer or something for these lights that I am missing?