Electrical problem Escort Cabrio Bj. 92

Hello together, the following problem: – There’s nothing going on at the back right: No flasher, no light, no brake light – pears are ok – cable plug sits perfectly inside – mass directly on the unit also doesn’t seem to be the problem: Everything is scratched free, rubbed, cable extended and held to clear mass: Nothing, no spark, nothing. Unfortunately, I don’t have a multimeter, but believe in that anyway… – That there’s no tension on it – cables in the trunk, no break to see. go from right to left, hit there the cables from left and together it goes forward… Front: – Sighting under the fuse box brought also no loose cable –> besides one! See picture! On this plug hang 2 brown cables. Mass??? Is this cable a track? If yes: Where does this belong? I found no free slot in which this could fit! Thank you Gruss Frank