Dash light issues

The dash illumination lamps are a trick and are the only ones wired this way.

The power for them comes from the tail/ park circuit fuse, TO the light switch, and then the light switch powers the dash lamp dimmer control. THEN the power LEAVES the light switch on the tan wire and goes TO the little INST fuse at one end of the fuse panel. From there, dimmer controlled lighting power is distributed on ORANGE wiring, to the cluster, ash tray, radio, where ever is a dimmer controlled lamp If you look into the back of the fuse panel you will see one terminal with a bunch of orange wires.

That might be tough to run down

Does it have an aftermarket radio? Maybe someone did a crap job of splicing. Do you have a column auto shifter? Maybe movement inside the column damaged that wire, to the shift quadrant indicator. I would for sure check the ash tray.

Do you / did you have a center console? It may have had a lighted shift quadrant etc, and the harness going to it, under the carpet might have been damaged.

If that kind of looking you don't find it, at the worst you could carefully clip the orange wires, perhaps one at a time and test them.

To avoid blowing fuses and to avoid damaging another light switch, get yourself a tail/ stop lamp and socket and wire in series from the battery to the test device. You can use that to jumper power to each cut wire. The shorted one will light the stop lamp brightly, but will not damage the wiring. Then solder/ otherwise splice them back into place.