65 dart turn signal wiring question.

Well I have time to work on it a little bit. This morning. I have turn signals left right front rear and indicators. But now when I push on the brake I only get right rear and front left turn signal goes off and on with pushing the brake panel. Now I'm lost lol I also noticed that the rear bulb sockets do not have any grounds as well as the front do not have any grounds. Does the dimmer switch have any effect on the turn signal or brake lighting?