... so I can switch from my 87 tails to my "new" 82-84 tails. I have the harness (2, actually), but I need the 84 wiring diagram to know what wires do what so I can connect up the harnesses accordingly.

 

The yellow wire is for the left turn signal, dark green wire is for right turn signal, light green wire feeds the reverse lights, brown wire turns on the tail lights, black is ground.
If the car has separate brakes from turn signals, then there's also a light blue wire for the brakes.
The only difference between the two wiring configurations is the presence or absence of the light blue wire, that's all.

However, if you are switching between these two tail light systems, you MUST perform a small wiring modification under the steering column.

Hope this helps.
Lou

 

:Edit: Should've done a search first, but I still might not have found the info here in this board, as it was posted in the History board.

 

Curious about that underdash wiring modification.

Also curious as to how I'm going to get these tails to work a la '93 Cavalier, with the outer 2 reds used as brake/park/turn lamps and the inner reds just park lights. I know I'm going to have to replace the flashers to do this, as the number of flashing bulbs changes...

I have these 2 diagrams to work with right now, and of course the one in my factory manual:

 

Okay, since nobody seems to know how to change the existing 87 wiring to work with the 84-85 tails, can someone post up a wiring diagram for a GTA or TA with the grid-style tail lamps, that seem to use a similar set up as the one I am building?

Got the tail harness all set today, with the exception of the body connector, which I have to get from a yard when it decides to stop being so crappy outside. However, I have one question: On the exterior side of the grommet, there is a separate connector with 2 wires running off of it, pink and black/white. It's long enough to go practically half way across the back of the car. What is it for, and do I need it?

 

That's for the fuel level sensor. The 82-84's had the wiring go behind the tail lights and under the rear bumper.

Hope this helps.
Lou

 

Strange way to run the wiring for the fuel level thing, above the muffler, I'd guess?

Either way... Snip. It's outta there.