JLM04A8L

Does anyone know the color for the pos/neg wires going to the reverse light on the drivers side inside the truck compartment?? I took the light apart to find a white and yellow wire going into the truck lid from the bulb socket but does not seem to continue out of the wire stack into the truck?? I am trying to install an aftermarket reverse sensor which requires tapping into the reverse light..

BTW: You know you have a high tech car when there are circuit boards inside the lights!! WOW!!

JLM04A8L

I forget to mention 2004 A8L...if that matters.

Bunky

From the wiring diagram, those lamps seem to be controlled by Module J692 "Left rear lid tail light control module." So the white/yellow wire doesn't continue out of the trunk lid. I think this module is in the trunk lid and is fed from a black 8-pin connector from the main central control module for comfort system (J393). This module should be located in the passenger-side compartment in the trunk, above or behind the battery somewhere.

Maybe either the violet/blue or the white/green wire coming out of that module would help you.

SlyAudi

On my 2014 A4, the reverse light in order to hook up a back up camera as follow: In the tail light housing, brown wire is ground, live wire is black.
Hope this help someone else, I could not the answer anywhere until I stripped and tested all the wires.
Happy hook up.

the_duke

This is the A8 D3 2003-2009 forum so I don't think this will be of any help to anyone. Also this is a thread from 2009.

slydog3333

Just joined to say this was extremely helpful for my 2016 A5. I was able to tap in to the black wire to get a reverse signal for my JVC radio. In the era of Google scraping sites it doesn't matter how old the thread is or if it's the right thread, Google will still find the answer.