Sorry, I don't understand your question properly as my english knowledge is limited.
So far, all what I can see is that the cabling to the trailer harness connector on the car's side looks intact.
I mean, that even when no trailor is connected, the left position lights are still off (like a fuse or a wire has been blown when that (rented) trailor which had a short circuit on the left light circuit has destroyed a circuit on the car's side.
Regarding the fuses: I only know about the fuses in the engine compartment. I have checked them; they are all ok.
Question: Is there an additional fuse compartment somewhere else in the car which I should check?
Regarding the harness: I have checked it around the plug on the car side: Seems all ok.
as I stated in the initial error description, the left tail light, the small position light on the left fender as well as the left position light built-in into the headlight do not work. So there are not the complete tail lights off, only all left tail lights.
But for example all (left and right) tail stop lights do work properly as do the turn lights and the reverse lights.