I have Napa single round tail-lights on the rear of my tub. The lights were connecting using the plug-in from the original harness.So here goes: There are 4 wires from harness plug to each tail-light. 1)red 2)green 3)green w/ white stripe 4)green with yellow stripe. The tail-lights worked by splicing red wire and green/white wire to tailights red wire. Then the green wire was spliced to the tail-lights black wire. I still didn't have signals so it stood to reason that if I double-spliced the green/yellow with the solid green and connected then to the tail-lights black wire,I'd have turn signals. Didn't work.What happened was the dash turn signal indicator stayed on for that side.That's all. So as it stands the green/yellow stands alone. I hope this gives someone enough info to tell me what I've got wrong.Also,do the front signals work independant of the rear or must they all be hooked up for the others to work. I replaced the front signals with a Napa bus light.Man,it looks good.But I still don't have any turn signals or brake lights. I'm getting there! Hey,I have ALL my lights now anyway! That's progress! Oh yeah,BTW this is on a '78 FJ40 we're working on.