I've found my 87 FSM schematics and have ditched the Haynes manual. Yeah...they are distinctly different. <img src="/forums/images/graemlins/angry.gif" alt="" />

Looking at the FSM, I now see where the common denominators are and have shot the GL wire (which turns into the WL wire) from the back end all the way to mid-harness where it crosses forward at the base of the passenger door and still have the same issue. I'm going to jump past the remainder and go straight to the steering column.

The common denominators which would affect power delivery to both the left/rear turn signal and the left stop light, but NOT the right/rear turn signal and NOT the right stop light are:

- the GL/WL wire (+) which runs from the left/rear combo light unit connector (supplies power to both turn and stop lights) to the turn signal switch
- the B wire (-) section which runs from the left/rear combo light unit connector across the back to join with the B wire (-) on the right/rear side (both sides share a common ground)
- the turn signal switch

A single power source (supplying power to both left and right rear turn signals and stop lights) runs from the hazard switch to the turn signal switch, then breaks out into two power sources from there, one supplying the right/rear and one supplying the left/rear. If the problem was the hazard switch, then neither left nor right would work (but the right side does work).

I'll check the B wire (-) by borrowing the B wire on the right side to see if things work. If things do work, the left side B wire segment is bad. If they don't work, then odds are that the B wire on the left side is good. Then I'll patch a new wire from the turn signal to the back. If that's good, then the GL/WL wire (+) is bad. If it's still bad, then odds are that the GL/WL wire is good and the turn signal switch is bad.

I'm just glad that I'm seeing some sense in things now.