Dash board lights stopped working - 1983 Cadillac Fleetwood

You don't say what the make model and year is, but generally the gauges get power from the same place the gas gauge does. Each gauge is grounded thru a sending unit or switch.
So my guess would be a problem inside the instrument cluster.

30 amp fuse near battery in a plastic box

1998 honda accord v6 fully loaded 191 k on it and my dash lights stop working and the lights where my ac control as well stoped too ,, i turn on the head lights an there no lights in the dash nor the ac contrlos what is it

MINE HAS ELECTRICAL PROBLEMS, DASH WORKS WHEN IT WANTS TOO, GAUGES WORK WHEN THEY WANT TOO,RT BLINKER STOPPED WORKING. I NEVER KNOW IF I HAVE GAS.

It's trying tell you there is something wrong with your brakes. Fix the brake problem and the light will stop coming on. Check your brake fluid level and check you brake pads for wear.

sounds like an electrical nightmare! start by removing the cluster,now try signals are they working if yes then bad cluster, also i had a few caravans that just had bad connections i removed the plugs and reconnected them and it worked fine, also with the light coming on with your foot on the brake may be a bad or in correctly installed bulb, check all brakeand signal bulbs, try all of this , good luck,hope this is helpful.

CHECK THE FUES BOX UNDER THE DASH BOARD ON THE DRIVERS SIDE.
THOSE LIGHTS ARE COMMONLY ON THE SAME FUSE

look on the left of dash for the switch you turn your interior lights on turn it see if your dash light will brighten.turn up enough brighten dash lights. dont turn until it stop or your interior light will stay on.

Check for a relay.