No headlights...

[67Dart273]

. I then unscrewed the dimmer switch from floor and unplugged it from it's 3 pronger connector. With the lights on at the dash I found +12 volts at two of the three connections. When I turned the lights off at the dash then I found no voltage on any of the three connections.Glenn

That is not how you make that check. Probe the rear of the connector with the dimmer switch hooked up and lights ON. Power comes INTO the dimmer on one terminal and goes OUT of the dimmer on a second terminal. If you unhook the dimmer, only one wire should be hot with lights on, that is headlight power coming TO the dimmer

If you DO have power coming out of the dimmer, and NOT at the headlight connectors it is most likely a bulkhead connector problem, or in the front harness

Have you checked the fusable link? that could cause this.

The fuse link will cause no power in any part of the interior