Perhaps something useful to start with here:Both revers lights worked on my 74 plate kombi when I changed out just needed to run another wire for the twin fog and re plug the loom for the lights. I also,need to code them in to remove the lights warning when I turn them on, yet to figure that with VCDS as my scan is just 1800+ lines of adaptions with a lot being in German

New T6.1 Tail lamps
I guess this is just an illusion as T6.1 halogen rear side lights(M2) are just 2 bulbs connected in parallel. That blows my theory out! I still can't understand why there would be voltage coming brown the brake light cables when the brakes aren't depressed.