Please go easy on me as I have never wired up a car radio and am completely new to setting this up. I previously had someone else fit an after-market headunit to my car, since then the front speakers were the only ones which worked. So I've bought and attached the PC9-404 cable: On the left of the picture below, the black plug which I've plugged to the red plug on the PC9-404 previously had nothing connected to it. From other threads I've been reading on this same topic here on Audisport, I assume this is for the rear speakers. I then plugged what is labelled as "rear -R" and "rear -L" from the radio side onto the other end of the red part of PC9-404 cable. I tried fading to the rear... and a massive amount of no sound was being played. Could anyone please help me here? I'm having a hard time figuring out what could be wrong. I even tried connecting the tiny blue and white wire to the antenna as I thought maybe that was the issue otherwise the wire seems to go nowhere and I saw someone else put it into their antenna somehow on another older thread and still no joy. Would it matter if my aerial doesn't work? I think I have the wrong adapter for the aerial and get no radio signal, but usually I wouldn't care as I only play music using the aux in from the headunit or off of the radios memory card slot. I'm really clutching at straws here... Any help with this topic would be massively appreciated!