I recently got a new issue with my 77 280z. all of my dash lights stopped working except my heater selector bulb. I've checked everything I can think of, fuses, grounds, I checked the bulbs and they're good, even changed the rheostat. all my other exterior lights still function normal, dome light still works. I'm at a loss as of what to check now. anyone else have a similar issue, and what did you do to fix it?