Have some Lights, but not others, Help!

1973 Plymouth Duster with 360. I have headlights, parking lights, all 4 side marker lights, horn, reverse lights, break lights and dome light. I dont have tail lights, dash lights, turn signals, fuel gauge not working, temp gauge not working.

I have replaced bulbs, socket PC Board and bypassed the amp meter. I replaced the step down capacitor , Fuses are good. So maybe it's the ground? Where though? Headlight switch seems fine. Standing by for the brilliance on this forum. Thanks - Snake Oiler