[DanEC]

After reflecting some more on the wiring diagram I'm backing off on the turn signal flasher. It feeds the turn signal power through a common lead so there isn't any reason it would work in one direction and not the other. That leads me to the turn signal unit. I guess I will resume testing around it later today. Probably feed it 12V power as suggested and try switching the L and R rear light leads to see if the symptoms switch sides also