Identified my Blown Fuse Problem
 

One of the minor issues I've had since getting the A8 is that it was continuously blowing the fuse for all the interior lights. I also noticed that when this happened, I didn't get the indicator flash when locking or unlocking the car. The alarm horn didn't work either.

After scouring the forum, there was a comment about the batteries in the alarm horn causing corrosion, so with Saturday being a good day and me being reasonably okay, I set about trying to locate the alarm horn, and this is what I found:

Two of the pins heavily corroded and part of the plastic missing:
http://forum.a8parts.co.uk/picture.p...&pictureid=464

Front and back views of the circuit board:
http://forum.a8parts.co.uk/picture.p...&pictureid=463

http://forum.a8parts.co.uk/picture.p...&pictureid=462

With this removed, I replaced the 10A fuse, and so far, everything is fine. If I'm up to it, a trip to the scrapyard tomorrow and hopefully I can pick up the alarm and maybe part of the loom.

Excuse my ignorance, but where that alarm circuit is board is located in the car?

The alarm horn is located behind the trim in the left side of the boot behind the CD changer. Didn't know where it was myself until I started searching for it, in all honesty. It's amazing what other electrical gizmos are lurking in there as well. Since the alarm was knackered anyway, I decided to pull it apart to see how much damage the leaking batteries caused.

Was thinking of doing a writeup on it for the forum, once I get a replacement, since it appears to be a common issue.

Wow - what a mess! Looking forard to write up and then I'll check mine.

Glad you got problem identified.+++