All the rear lights work except for the reverse lights. I've checked this thread: https://www.rx7club.com/1st-generati...t-work-781213/ and that ground is fine. Also all my fuses and fusible links are fine. Bulbs also check out.

There are however a lot of things unplugged in the back, and I don't know what they all go to? Can anyone outline for me what connectors are related to the reverse lights?

People say the switch on the tranny gets unplugged or broken sometimes, how can I test this with a multimeter? Can anyone tell me where exactly this switch is located as well? Like a picture of it on your car would be awesome - I looked at the FSM but the pictures suck and I can't figure out where exactly it is. Looks like it's on the right side, but I dunno. I tried looking at it tonight, but my car is too low and I don't have a jack here.

 

Here's a picture of a GSLSE tranny, backup light switch is the same on a 12A tranny. More pics in this thread https://www.rx7club.com/1st-gen-arch...ctures-706258/

 

Awesome that was exactly what I was looking for. Any more ideas on my issues?

 

its a really simple circuit AFIK, i think the circuit goes like this. battery -> main fuse -> ignition switch -> back up light switch -> back up lights -> ground.

you should be able to unplug the switch, and jumper the car side and the lights should work

 

The tail light assembly has one large plug in it, and you said all the other lights work so it can't be that.

Refresher:
S - bone stock car
GS - better sound system, some other accessories
GSL - power windows, power locks, rear hatch wipers, etc.
GSL-SE - same as GSL but with fuel injected 13b

That is a very simple list, just showing the progression.

I have an 84 GS as well and there are a TON of unplugged wires in the back of my car as well. Also underneath the coin holder there are a few plugs that I can't figure out where they go. The plugs in the back that aren't used are for accessories that we won't use. Most of them you shouldn't worry about, unless something isn't working.

 

on an manual trans car there are two unused bullet connectors, and you should NEVER plug them together, as its for the AT shifter light, and without the resistance of the bulb, it will blow the variable resistor.

in the rear, there is a plug for the rear wiper, washer... everything else is used in an 84-85 car