Classic/Antique Car Repair: Brake lights, light sockets, turn signals

Question
I have a 1966 Ford Mustang, the running lights work but the brake lights and turn signals only on the rear of the car do not work. The turn signal lights on the front work.

Answer
The brake lights and the rear turn signals use the same bulbs and the same wiring from the directional switch to the rear of the car. There are three possible common problems:
1. Both bulbs on each side of the rear of the car are blown. The first step is to replace them.
2. The grounds on the tail light sockets are bad and will not carry the higher load of the stop and turn signals.
3. The directional light switch is defective as it controls whether the light will be stop or directional.