The interior light dimmer located above the headlight switch controls the instrument cluster lights as well as the center console lights, and the auto tranny shift position indicator if you have an auto tranny.

If all the above are out, the dimmer is most certainly bad, or disconnected.

Dimmers do go bad. Can be bypassed with a jumper wire at the back or the dimmer, or replace from a junker. Maybe also available from fcpgroton.com

These are an old-fashioned variable resistor.