No brake light or tail lights

[Nate781]

I need some help please. I have been working on a 1970 C10, I've replaced mostly all of the wiring harness on the truck. Expect for the Engine harness and turnsignal switch. I have no brake lights or tail lights. All ground straps are correct for that truck, ive added some extra ones thinking it was a ground. Im thinking it could be turnsignal switch. I know that the main wire completes the loop of the tailights but Im running out of ideas.