New harness problem

So far as the starter not working, that should be easy. You found it. The brown wire is bad.

So far as the lights,

This is troubling. I assume you say "no lights" you mean both headlights AND stop/ tail?

The light switch has TWO separate power sources, in other words, the light switch is really two separate switch circuits hooked together.

The headlight part gets power from what is called "the number one splice" inside the under-dash harness. If you look on the diagram, follow the original ammeter feed wires, theres a big splice which feeds off to the headlight switch, the ignition switch, and the "hot" feed to the fusebox. Maybe that splice has failed. Original Mopar splices were welded and I've seen at least 3 cars which had a failure in that splice, over the years.

Anyway, from the splice, it goes to the headlight circuit ON the headlight switch, which has a breaker (auto reset) mounted right on the switch.

THIS circuit only supplies power to the headlight, NOT the tail

Tail part of the circuit comes from a fuse on your fusebox.

Do you have power at the fusebox? At the headlight switch?

MIGHT just be something like corrosion setting into a fuse clip or similar.