I have a 2002 A4 1.8t . My problem is all my taillights work except the passenger side lower left corner light (running light). I changed the bulb with multiple bulbs that all worked but it would not light up . It seems like its not recieving power. The wires all look good as well as the socket areas and assembly . It also is not showing on my guage cluster that it is out . So to prevent myself from getting pulled over i pulled the other sides matching bulb out and that popped up on the guage cluster as rear fog light out but the other side did not . Next step isto check and see if im getting power to that individual socket . My guess is im not getting anything so i have to get a whole new light panel . Any help would be greatly appreciated .

 

chances are its a bad ground but a quick fix would be to run a power wire from the other side light to that light

 

Checked the fuse?
there may be one fuse for each side?
or get a tester and test unit
Or swop over the light units if the fitting are the same to see if the light work
befor you go and get a new uint
Trev

 

The fog light should only be on the drivers side. I suspect you are trying to get a light to work that shouldnt. When you first pulled it apart there was no bulb in the socket, correct? That is where the right fog light would go if it was available. Put the bulb back in that threw the fog light out warning. Turn the headlights on, but dont pull the switch out. You should have two bulbs on each side on. The outer ones and the center one. Pull the switch out one click and your front fogs will come on. Pull the switch out the second click and your rear foglight should come on. This will only be on the drivers side. It will be the area closest to the center of the vehicle. The right or passenger side should not illuminate.

 

Thanks for all the help to everyone who replied. No there was a light in the socket when i pulled it apart . It is the bulb on the bottom of the light closest to the trunk (bulb located in the rectangle reflector part of the light housing ). I believe its the running light . I looked at my friends car and its def a light that should be on as soon as you turn the lights on . Also the other side always lights up and it looks like a bulb is clearly out on the passenger side. I believe each side should have two bulbs that are on as soon as the lights are turned on . I think the best solution is to just buy the new light socket board . I called Audi its around 15 bucks . But i was just giving it a shot to see if i could fix it for free.

 

I'm with Dank. I think it's your rear fog. Especially since you say you pulled the matching bulf on teh drivers-side out and got a fog-light warning... U.S. market Audi's do NOT have 2 rear-fog-lights, I don't believe. Only the one on the drivers' side should light up (unless you go doing some wiring/modding, that is.

 

Black On
I'm sure there are more AUDI "rocket scientist" amongst us here...but let me share a similar experience. I bot a 96 A-6 in OCT 05...mint. Aside from a clim control unit malfunction. my L/driver side(rear) running lite did not illum in mid or high position of short stalk stick. A euro mechanic friend jumped out R side to left side and everything was great. Two month later R side running/park lites went out thus L side was out-fuses perfect, just now running lite and could not ID short after exhaustive efforts. Euro buddy lifted black plastic fuse/relay cover near driver firewall-found running light transfer diode/relay(or whatever he called it) was loose-#374-
pushed it in and all rear tail park/running lite worked-R to L jumper removed and everything still illuminated. It was simply this 374 needing reset/push back into connector socket. Sounds to good to be true...I agree, but that stoped all the rear running lite problems=NO $$
geno