<!-- from fixya rte -->No dash lights ? Mercedes - 2000 Mercedes-Benz S-Class

Fuses can be bad, even though they look good, and connections may be corroded so there is not a good connection for the light. Double check to ensure bright metal contacts.

fuseboxes normally are in one of 3 places..under the drivers dash.. in the glovebox.. or under the hood near the battery..dealer can say for sure..

there is a government safety recall on the dash light instrument panel from Mercedes at no cost. Contact Mercedes for more info, my dealer had no clue about this so the instruction had to be sent from Mercedes to the dealer.
I assume you checked the fuses first

Believe it or not, but there is a bulb that illuminates your instrument lights. These are not intended to go bad, I would look into a bad fuse, although unlikely it is also possible the light had blown.

Hi. Thanks for your question. For issues related to brake warning lights on dash illuminated for Mercedes C180, 1996 saloon. You can visit https://www.reliable-store.com and download the entire workshop manual which includes all the information along with the diagrams for better understanding. Good day!

Do you maybe have the dash light dimmer control turned off?

If nothing is broken, check to see your dash light dimmer isn't turned all the way down. If you have automatic lights that turn on at dusk and you place something over the light sensor (usually on the dash board), the headlights will come on during the day and set the dash lights to the dimmer switch setting.

Remove the metal part of the ashtray, you will see two screws that hold the ashtray plastic part on, underthis is the screws for the lower panel
You can now carefully lift the whole panel away.

First
Make sure your dash "dimmer" is not turned all the way done, its a small rod thats twists clockwise to increase dash illumination, counter clockwise to decrease...
Next..the bulbs in the back of the gauge cluster might be burned out , if they are the original bulbs, thats probably the case...

Sounds to be a loose or corroded wire/s at either starter motor or at battery fusible links.
Also check the earth strap (Cable) between engine and bodywork.
Hope this helps, MMP