When getting my trailer ready for the road I checked the tail lights
for operation. The left stop/tail light
did not light
. After spending time checking for ground and wire colors from the plug to the light
I decided to check the colors at the plug. What I found was that a tiny spider had taken residence in the wiring connections in the plug causing the left turn and stop circuits to fault. I gave the spider a good dose of WD40 causing it and the web to fall
on the drive after which I stomped on it several times.