lighting on 2004 Audi A4 Quattro

well on my audi i have rear fog light. i just bought the car about 2 months ago. and i turn on all the light fully and find that one of the rear fog light was out. but then i check the bulb and there wasn't a bulb in there. then i went out and bought a bulb from napa. and place in the new bulb. but then now it still doesn't work. so i thought it was the bulb then to took the other side off and use that old bulb from the working side (thinking that the new bulb wasn't the right one). but then it still didn't work. so what i think the problem is that the rear socket for that rear fog light is broken. therefore i would have to replace the whole board because its a one piece where all the rear bulb are connected too. include brake, reverse, rear fog, and turn signal. so my question is, is it the rear lighting board that i have to replace or can i just replace single socket?( if i can replace the only rear fog light socket, how when all of then are on one board.)

Asked by for the 2004 Audi A4 Quattro
left side only on rear fogs (cars pass on left in germany). later models use 2 but are called driving lights.
2 answers
If I recall, only one rear lamp is supposed to come on when you have the fog lamps turned on. This way people don't confuse them for your brake lights. I would check your owners manual to be sure though.

To answer your question, it is possible to change a socket if you are comfortable doing some work with wiring. That empty socket may be used in other countries for features not offered on US spec cars. hope this helps!