cocZamudio

It's a bit late, but I'll add my experience to help others searching for a solution to this problem: The RED wire by the rear view camera needs to be connected to a backup lamp powered when the car is in reverse. The BLACK camera wire needs to be well-grounded to the chassis; I installed a ring terminal on the ground wire and used one of the taillight mounting bolts and a couple of external tooth lock washers for a good "bite" through the paint. At the A6 head unit, the rear view camera YELLOW RCA plug goes into the YELLOW RCIN (rear camera input) socket. The RED camera wire connects to the PINK A6 harness wire marked "Rear Camera +" which is the reverse gear detection wire. To recap, the rear view camera RED wire needs to be connected at both the camera end and the head unit end. The BLACK camera wire needs to be well-grounded; a failure to ground well is often a cause of camera malfunctions. Having looked at several different cameras it seems the RED power wire, the BLACK ground wire, and the YELLOW video cable seem to be industry standard colors but there could be variations. Hope this helps!