My DIY brake controller and power feed to 12 pin Aussie socketinstall
Thanks to the info provided here, I quickly determined that my new-to-me 2014 TDI does not have the brake controller wiring to the dash area, but the wires do exist at the green plug. As well as a brake controller install, I wanted an Australian 12 pin socket wired to suit my Jayco camper trailer. This required a 15A "ignition" circuit to power the 3-way fridge while on the move.
So I needed an additional 3 wires from front to back, and additional 1 out through the body to the socket. Turned out there was a "spare" I could use for the latter.
All my wiring details are documented in the PDF attachment. I could have made a 13 pin to 12 pin adapter, but thought it easier and more reliable to just cut off and replace it. There was ample slack in the loom giving plenty of room to work. I also added a "trailer detected" LED for confirmation. Even though the trailer has LED lighting, it is detected ok. It's supposed to take 5W load minimum for that; perhaps the lights have built-in load resistors or the trailer controller has been adjusted in later models due to the prevalence of LED trailer lights I will do some tests when I get time...
At the back I just cut the 3 wires off at the green plug and joined them with male/female spade lugs to lengths of 4mm wire. Running 3 wires to the front was quite easy; no need to actually remove all the trims, they can be poked through to the back seat area with a bit of stiff wire, then just be tucked under the trim edges a bit at a time. Select a couple of empty fuse slots that are on the "ignition" circuit and use fuse taps with 15A fuses; one for the brake controller and one for the power feed.
Hope my first post on this forum is useful for others