Leaderboard

The a7 is based on the a6 chassis and running gear. Here's a video which might help: Cheers Steve

Glad you got it sorted out, and glad too that you analysed the problem and reported back. It may help others to know what a water leak can do.

Manage to get the bottom of it after alot of faffing around... My inner/boot tail light LED wasn't working because it's live feed is taken from the live feed on the outer tail light. The outer tail LED driver board had previous water ingress causing that LED to partially illuminate but not enough to notice it was at fault (at first). The LED driver board was also not outputting enough juice to supply the inner LED. I took the lights out and because I couldn't find a wiring diagram I buzzed out and took the voltages across the contacts, that gave me enough to know that outer LED feeds inner LED so I buzzed out those link wires (marked in blue in the picture)....all good apart from lack of volts on the passenger side. Anyway, replaced the entire outer cluster on the passenger side which now kicks out the correct voltage to the inner and happy days! If anyone is interested I've attached my scribblings for my variant of A3. It shows the cable colours, connector pins and continuity between ground and live with lamps inserted. (with cluster and bulb housing removed from car)...hope it helps someone out. Thanks for all the suggestions

Hi Lisa, Just changed mine as the old ones were fogged on the inside! Thought I would upgrade also but it is hard - assuming you have halogens then upgrading to HID or LED is problematic for 2 reasons: 1 - the electrics from the main headlight switch (and also possibly determined by the ECU) are set for halogens and you need a major electrical upgrade to change to HID and LEDs; 2 - the light unit itself is designed for halogen bulbs and HIDs/LED may not give the correct patters, and may fail MOT. I bought used headlight units on eBay for about 20 quid each and then stuck Osram Night breaker halogen bulbs in... Changing lights mans the front bumper guard has to come off - not too epic but not a small job HTH

Thanks for the info Steve, got mine 🤘