70' Dart rear wiring harness

BINGO
Bear with me while I tell you about cousin Jack. He was a dang good carpenter and a bit hard headed too. He got a ticket for no brake lights on his van and was just not gonna believe the turn signal switch was the problem by my telling him over the phone. He had to drive the thing down here with no brake lights so I could prove this to him before fixing it.

Now to diagnose and prove to you...
one wire at the brake light switch is hot at all times , the other is hot when pedal is pressed. That should be a light tan or beige wire.
Rather than pressing the pedal lets just shove a hair pin or cotter pin in that connector as jumper.
Now take the test light to the long flat connecter at steering column and find the same color wire hot there.
Now you see the brake light power going up the column so try and find it comming back down on both green and orange wires. If it aint there replace the turn signal switch.
Later were fix your reverse lights.