Dash light issue

[Johanswe]

Hello. Just bought a 528 from -85. I only get dash light when the light switch is in park position. The rest of the interior as the climate controll light up too. But when i turn on the headlights the dash and the rest goes dark. I have open the light switch and cleaned it but did not help. What could be wrong?

[RoundTailLight]

The "headlight on" contacts could be fried and "open." This light switch is commodity and used on many models. I have a very good used one on hand from my '85 e28 parts car. Check for voltages on outputs of switch to see if opens exist.