Mk5 Taillight issues bad wiring or CECM??

[twizproductions]

Issues with brake lights, turn signals, and running lights in the rear of the car everything to do with the front end lights work just fine. Could this be a wiring or CECM issue? Because the owner before me had done some weird custom wiring for the back tail lights and volkswagen corrected the wiring and now the lights do not work at all i had taken the vehicle in a few days ago and they said its a possible wiring or module issue how would i go about fixing and diagnosing the issue so i do not have to spend a fortune at the Volkswagen dealership to correct it. I will provide some photos of the wiring if needed thanks, Tyler

[Neilios_Wol]

Hi what age is it? I remember on some the wiring loom used to rub against the battery tray and down by the abs pump. Might be worth pulling the battery and tray out to check for signs there.

I had one one where one of the rear lights refused to work and it was a broken wire in that area.