Dashlights are out- need some help

[ThillyGooth]

Hey All,
I have a 1993 400E. Recently the dashboard lights went out. I have tried adjusting the knobs with no results, so I know it isn't that. The lights on the AC/Heat displays have been out since I got the car, I never even knew they could light up. All of the warning lights and hazard warnings still work and light up, like all the ones in the row with "parking brake." I was wondering if anyone has any suggestions for bringing these lights back. Are there some fuses I could try swapping out? Also, my headlights and brakelights and all of the little fog lamps and stuff go out very frequently, I was wondering if this could be interconnected either through fuses or some sort of overall electrical thing. I have heard that this sometimes happens if the battery is overcharging everything, does anyone know the ideal voltage it should be at when the car is on? Thanks.