Hi, I have a 2016 Nissan Sentra. When the lights are switched on, only the left rear tail light doesn't come on. Brake lights work, indicator, hazards and reverse. I've checked the fuses cabin and engine bay. I've swapped part of the loom/wiring that can disconnect to test with the right hand side and the light works on the right hand circuit. I've tested the right hand side light on the left circuit and the issue occurs hence it only occurring on the left circuit. As mentioned (bulbs, fuses checked/tested). I've tested the first section of wiring which can disconnect too and that's fine. Only additional section not tested yet is the towbar wiring which does scrape when exiting the driveway. Could this affect the left circuit or should I check for something else? (It is a right hand drive Sentra)Thanks in advance

SOURCE: all tail lights work except the left brake light,

No. Check wiring or socket.

SOURCE: Brakes Lights dont work on a 2006 Chevy Silverado

I've worked on these the first drove me crazy. its the turn signal switch every thing runs thru these. head lights, turn signal, brakes. except the third brake light. it runs directly from the brake switch. go figuare

SOURCE: Need to solve towbar wiring fault for trailer

This sounds a bit crazy, but you do not have a good solid ground to your trailer brake lights. You may have to run a separate ground wire from the trailer to the car. Pull your trailer close to the front of your car, close to the battery. Use some wire to connect your trailer to the battery. Then touch each contact one at the time until you learn which port turns on which light(s). Using the wires, only one in the ground connector and the other in the brake connector. gain access to one or both sides of the trailer lights, use another wire and touch the base of the bulbs to the metal of the trailer if the light gets brighter you need to run another ground wire. Hope this helps FixYa up.

SOURCE: Brake light bulb Issue

A bad socket is a common enough problem that it is likely that, rather than a wiring problem. Just splice in a new socket, if you can, or whatever is easier and cheaper (like a tail light assembly from a salvage yard).
Of course if you have a voltmeter or testlight, you can check at the socket electrical connector for power when it should be there-when the brake is pressed.