1995 Buick Regal Instrument Panel lights go off when the li

Greetings,
My instrument panel lights go off when the headlights are turned on. Not just the instrument panel, but the radio and AC control lights go off also. The radio and AC lights are on when the lights are off. All fuses check out.
I guess it could be the dimmer switch, but the switch will turn on the interior lights when clicked to the on position.
I am thinking there must be a relay which redirects the instrument light juice from a lights off circuit to a lights on circuit.
If there is such a relay, does anyone know where it is located? Should I just pull the dimmer switch and see if it is working?
Regards,
John