I have a 2000 Audi A6 2.7T Quattro and I been having issues with the license plate light. Actually not having issues... IT'S JUST NOT WORKING!!! I dismantled the inner part of the trunk to check the wiring (keep in mind that I don't know exactly what I'm looking for) and even the bulb housing itself. Of course I've replaced the bulb and still nothing. Is it a wire? Which one? Fuse? I can use any and all possibilities to help right now. How can I resolve this without having to take this up with an Audi dealer???

 

First, get a multimeter or even just a 12 volt test light. Then pull the two plugs back behind the trunk lid liner and find if there are 12 volts there when the lights are on. If yes, you know the prob is the bulbs or the bulb sockets. They are known to corrode into a mess, especially at the age of these B5's. if you can't test 12 volts at those plugs, now you can talk fuse or some other wiring prob.

 

He has a 2000 A6, not a B5. I just thought i would point that out in case you missed it. I figured you were giving him technical advice, based on a B5 and not a B6.

 

His A6 is actually a C5, but besides the point the connectors in those housings end up getting corroded, try cleaning them with a wire brush. Also the can get bent and not make solid contact, make sure that isn't the issue as well.

 

Missed it, you're right. At any rate, the principal is the same. Find out if there is 12 volts back there, then trouble shoot from there.

 

Gotcha!

 

We have an 2005 A4 my lights are not working. One has 13 volts over side has -13volts. Can someone help me thanks

 

Not possible. They both share the same ground so the polarity has to be the same. You just swapped the red and black leads when you tested. If you have 13 volts there, either the contacts are corroded or the bulbs are shot.