Headlights, dash lights & front side markers not working

[71 C20 CS]

All three just stopped working. After they stopped working I did a ground up rebuild on the front end and installed a new front wiring harness so I know it’s not up there, I also put in a new headlight switch, didn’t fix the problem either, checked the wiring plug to the switch and it has power.

Is this a ground problem? The parking and tail lights are part of the switch and they work. Any insight would be greatly appreciated.