bradwilcox

All fine on this 5-speed. Then, suddenly, no back-up lights. Confirmed trunk wiring is good, fuses good, all good. Nothing was changed or worked on. Previous owner told me that this happened to him once before and I should unplug the cable down in the engine bay between the front wheels and re-seat it, and spray some cleaner in while I'm at it; that worked for him. I did and no dice.

Bought the like-for-like part 012919823A, still new, from UK ebay, that plugs into the transmission and sends a short cable into the engine bay. Could not get my hand in there to replace the part on the transmission case, so I paid a good shop to do it. It worked for a day. Now back to blowing the fuse. I have the part unplugged from the engine but still seated in the transmission.

Any ideas?

What are the functions, plural, of this part, by the way?

If I made stupid errors -- I am learning cars and Audis.