76 Dart no lights

Hey folks, so I've been fixing a few electrical gremlins in my 76 Dart. I'm down to my last two. No power to the radio which isn't so much a big deal, but I also have no power to all of my lights. I tested the connection at the firewall, and there is no power coming out.

I printed out a wiring diagram for the car, and studying that, I'm thinking it is either the ignition switch, headlight switch, or the "printed circuit connector". I have blinkers, and 4 ways, but that's it.

None of my gauges work either as far as I know.

A few questions.

1. If the ignition switch is bad, will that cause the lights not to work? I don't even have brake lights, or dash lights.

2. Where is this "printed circuit connector"? and is there anywhere you can buy them new?

3. Could just the headlight switch stop all the lights on the car from working?