Rear tail lights

Have you tested the globe? and check for power at the globe holder and also check that the earth is okay, if the other light is okay, the problem will probably be at that light.

Actually no. But I will check and get back.

Okay, always best to check the basics first.

I do not have voltage at the lamp when the brake pedal is pressed. I would run a jumper from the left brake light to the right but I do not think that would work since both the tail lights are separate runs altogether.

most common things are a bad ground {even if they look good} a broken wire or a bad brake light switch,