Maybe this will help. My car is a 71 z.

Lower left green wire is for turn signal which is R/W in the harness

Lower right wire is reverse which is R/B in the harness

Upper green is tail light all blacks are ground. Which is G/W in the harness.

The other light is brake. However I installed another 1157 socket So I would have both of the top lights tail lights and brake lights. I also installed led bulbs.

Hi Patcon , here are some Fairlady Z series’s wiring , hope it helps you a bit .
 

Kats

Thanks Kats

Can anyone post up a JDM or Euro version of the wiring diagram for the tail lights to identify wire colors? @kats @jonbill @HS30-H

48 minutes ago, Patcon said:

Can anyone post up a JDM or Euro version of the wiring diagram for the tail lights to identify wire colors? @kats @jonbill @HS30-H

The 72 FSM has the colors.

In @kats connector it does not show a Br or BrW wire. It shows two GW.

This may be the correct orientation:

Edited yesterday at 01:54 AM1 day by SteveJ

So factory operation of the JDM tail light??

Reverse is reverse

Turn signal is turn signal and flashers

Both upper red lamps are parking lights?

Only one upper red lamp is brake light? Maybe the outboard one?