Audi radio change

Titzon Toast

I've tried searching on here and on Audi forums without any luck and I'm hoping that someone can help me out please.
I bought a harness adapter in Halfords today so that I can put in a single din Sony head unit instead of the standard double din Audi Synphony unit that came standard with car car.
There are three block connectors coming out of the dash and I connected all three of them up correctly but I'm not getting any sound from the back speakers.
The car doesn't have any steering wheel controls or the Bose system as standard so the adapter I bought should be the correct one.
The guy behind the counter checked it up on his computer and found me the corect one for my car.
Hopefully if I can get these pics to load it might help.
Thank you in advance for any advice received!

EDIT.
I should have added, the car is an 04 A6 diesil if that makes any difference.
Thank you.

TherapyBoy

Your rear speakers are amplified. Try running power to the blue/white wire in your second photo, you should be able to power it from 12v ignition circuit or the power aerial output from the radio itself, normally a blue wire on radio harness or on the loom you got from Halfords.

Titzon Toast

Thank you very much for the reply.
I have a small amp and a sub that I was going to run with the new head unit, it's a set up I've put in my last few cars.
This built-in amp business just complicates things now!
I'm heading over to my buddies house tomorrow morning so he can have a look at it for me.
Do you have much experience with these systems by any chance? Could I theoretically run my small sub from the existing amp?!
Thanks again btw.

TherapyBoy

You can't run your sub from the existing audi amp, even if you could it's probably so low powered it wouldn't drive the sub anyways. Just use the amp you have for the subwoofer, run it off your pre-amp outputs from your new Sony like you would in any other car.

debabyjesus

You need to put 12v to that blue and white wire hanging loose in the picture. Even if you do that you will probably end up with noise. Some people power the rears direct from the speaker level outputs from the new head. Bypass the rear amp altogether to avoid noise, ideal in your situation as your installing your own sub/amp anyway.

I see you've got the climate control button wear aswell, you can get new stickers on ebay for very little, bit fiddly to install but looking at worn buttons annoys me. You can get just the plus and minus buttons on their own, which is all you need.

Titzon Toast

Thanks again the great replys lads. It's in and working now, it was indeed down to that blue and white wire mentioned.
Also, I did actually notice a little bit of feedback noise coming from the rears. When I get around to nailing in the amp and sub I might see if I can bypass the standard amp and run the speakers directly instead.
Thanks for the heads up about the buttons too, I'm told it's fairly common with these cars but it drives me spare. I'm definitely going hunting for those stickers now!
Thanks again.