I'm just asking this question on behalf of my Father In Law, who owns an A4 B6 Avant Sport Quattro, 2003 MY.
When reverse parking his car, he noticed that his nearside brake light wasn't working. He thought it was a simple bulb change, but on doing that it still didn't work. The middle and offside brake lights are fine, and there is no bulb failure warning on the dash cluster.
He switched the working brake light bulb for the non working one, just in case it was a faulty bulb, and still the nearside brake light doesn't work.
He checked with a multi meter, and there is no + 12v getting to the bulb holder, but the wires as far as he can see look ok and don't have any breaks in the them. The holder itself is not corroded, and the tracks in the cluster seem ok too.
Where are the earth points on the A4 B6 Avant? Does anybody have a PDF they could send me from ElsaWin or similar? It couldn't be the brake light switch could it, as I'd expect all of the brake lights not to be working if that was the case? All the other lights work fine.
Any ideas before he carts it off to the stealer?!
(PS I would VAG-COM it for him, but he's 200 miles away!)
EDIT: Found a wiring diagam for the rear light cluster. It's a Highline car, and I see that the bulbs are supplied from something called the J519 voltage control unit. I've read that it can cause the problems above, but where is it on the car, anybody know?
Thanks in advance for any help guys.