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?

9 hours ago, Patcon said:

Both upper red lamps are parking lights?

No, the Japanese market parking light system has its own bulb in each rear lamp unit. It's the one that is otherwise blanked off with the 'P' plug/grommet in the centre of the lamp unit.

9 hours ago, Patcon said:

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

Both upper reds operate as side lights and brake lights.

Am I dreaming or do I remember correctly that someone somewhere had created a plug-in pigtail that 'converted' our US based wiring to the JDM for use with the JDM lens? The purpose of the pigtail is to prevent from having to cut into the factory wire harness.

Edited 6 hours ago6 hr by texasz

I bought mine from Futofab.com and they were plug-up and go. No changes on my end.

15 minutes ago, texasz said:

Am I dreaming or do I remember correctly that someone somewhere had created a plug-in pigtail that 'converted' our US based wiring to the JDM for use with the JDM lens? The purpose of the pigtail is to prevent from having to cut into the factory wire harness.

This maybe?