[Richard / E320]

I'm still sorting out some minor problems or issues on my 1987 420SEL... when I turn on the parking lights or headlights, the 'bulb out' dash warning light comes on. I've checked all parking lights, headlights, turn signals, tail lights and brake lights; all seem okay. I did notice that when I turn on the right or left 'parking' light, nothing comes on.

What might be the problem with the warning light coming on when all bulbs are functioning, but the 'parking' feature isn't working?

Thank you,