No sound from rear speaker after installing aftermarket with this head

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Hi,
I am trying to install aftermarket stereo in my audi a3 2006. i purchased the adapter PC9-404 from ebay, initially there was no power in the stereo so i connected the yellow wire to the red one now the power comes to the stereo. however the rear speakers are not turning on. I also connected the blue wire of the with the red connector to the red wire (power), but still now sound from the speaker.
can someone please tell in detail what i need to do, can i make this connector work or is it totally wrong?

I think i have non-bose system, also i do not know if the amplifiers are working or not, a bit new to these things.
i attach here the pics of cables from car, cables from stereo and adapter (head) unit. There are 6 pins in my black iso connector of audi, while there are plugs in the red iso connector plug of the head unit. I do not know what the 2 extra pins are for.

Thanks in advance.
 

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The blue wire is a remote wire ie it only powers up when the stereo is on ie for amps
 
The stereo turns on, the front speakers works but the rear not. actually there is no difference if i connect the stereo with this adaptor or without the adaptor
 
I had the same issue on my last a3, there are 2 connectors that can be used, you may just have the wrong one like I did
 
do you know which one is the right one that you have?
 
I'm not sure mate, was on my last A3, changed to a newer one about a year or so ago.
I ended up taking it to an auto electrician who sorted it for me, it was he that mentioned the 2 different leads, sorry I can't help any more
 
No problem. Thanks
 
The red and the yellow wires are permanent live and ignition live, you may not have a ignition live so you may have to have them both connected together but the radio will not turn off with your key. You will need to find a decent ignition live from the fuse box and run it to the red or yellow wire, the easiest way to find out if the permanent live and ignition live are the right way around it to try save a station, take your key out and if the station is still there when you power it back up then it's correct. If not you will need to swap the red and yellow around. The brown plug is your speaker plug, the wires in it are each front speaker positive and negative. Your back speakers are not wired through that plug and I am pretty sure they are run off the standard amp in the boot? If the amp isn't powered up the rear speakers will not work. You need to take the amp/sub output from the black wire and wire in a ignition feed to the amp and connect RCA leads to the sub output on your radio. A little bit complicated, the best way is to take it to a car audio shop. Where are you based? My uncle owns a car audio conpany in manchester
 
@Scott_Crossley Thank you very much for the detailed reply. Yes i have read about that always ON problem and i will use a wire from the fusebox later on to solve that issue. First I need to get the rear speakers working. I am not quite sure about the amp in the boot, but i think yes its standard, no changes, so it must be there. I am not from UK, border of france/belg, its a bit expensive here and also i want to do it myself.
Please clarify this last part a little more
"You need to take the amp/sub output from the black wire and wire in a ignition feed to the amp and connect RCA leads to the sub output on your radio".
Which amp/sub output from which black wire? there is no black wire in the red iso connector or the black big iso from the car.
Yes I have connected the RCA leads to the new radio.
 
I am having a very similar issue here and will be watching this thread.

After new head unit, my front speakers work, back ones aren't. The headunit I have has the same connector like my car (ISO) though. But my guess is that solution should pretty much be the same.
 
There is a blue wire in my adapter (connected between the two black iso) but it is not marked with anything like amp etc. Do i need to cut that wire in between and connect it to the blue/white cable coming from the red iso?? as i understand so far it will provide the power to the amp, but i have already tried to connect that blue/white cable from red iso to the live (red) cable but the speaker were not working.
 
On the electrical drawings on the top of your new head unit you should have a blue wire marked up Amp/remote wire, connect this to the blue wire on your ISO. Try this and connect the RCA leads up, what I wrote yesterday was me thinking you didn't have the lead with the RCA leads already on them so partially ignore me lol
 
there is no marking of "Amp" on any wire, there is wire which is open on one end and marked "Remote/steering wheel remote" which i beleive is not the one for amp. The other blue wire which connects the two black iso is not marked with any lable, is that the one i should connect to the iso's blue/white wire? but will it make a difference because i have already connected the blue/white wire of iso to the ignition source and there was no sound
 
looking at the first picture ,there is only wires for the front speakers , 4 more wires need to be put into the iso block , unless your taking a signal from the stereo to an amplifier for the rear speakers
 
also i tried now to connect that blue/white wire from red iso to the blue/white wire on the stereo but still not working, even connected that blue/white wire to the ignition source but nothing worked.
any ideas please?
 
Are you sure? and which blue wire, the one coming from the stereo or the one coming from the red iso harness
 
If you can take a better pic of the red connector from front (not angled one so I can see properly inside) and back I can explain in detail what to do since I managed to connect my aftermarket stereo 2 days ago and it is working like a charm :)
 
@hollow yes you are right there are 4 wires only for the front speakers, but from where should i take the other wires?
 
@Rideen Thanks, here is the pic, there are only 4 pins, while from the car (black iso) there are 6 wires coming which plugs into this red connector, not sure if the 2 are useful or not.
 

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here is the back of red iso and also the total connections in 2nd pic
 

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Blue/white wire from red adapter should be connected to +12V red wire that goes in the stereo as well. So cut the red wire a bit and feed some signal from it to blue/white.

Black wire from red adapter needs to have GND connected to it. So cut it open a bit and bring the GND (ground) signal to it. You should have GND signal as a black (or brown) wire going into the stereo as well.

Basically you need to power up the AMP with +12V and to send it proper GND. This will work 100% as that is what I did to mine.
 
I have already tried connecting the blue/white wire of red adapter to the +red that goes to the stereo but it did not work. About the ground to the black wire, i think there is already the brown cable of the black iso (from the car) which is directly connecting to this black wire of the red iso when they are plugged in, if you look closely the second picture. so isn't that ground from the car enough for this?
 
Also the purple and green wire coming from the stereo, which is for the rear speakers to power them, does not plug into any wire in the adapter actually (empty pins on the other side), you think that may be causing the problem? or would it be enough to power up the amplifier then there is no need to give power to the speakers?
 
Your AMP is not getting enough strong GND in my opinion. The black wire is going to RCA cables which have bad ground, that is why I intercepted the black wire signal and gave it better GND and my AMP and rear speakers got powered properly after that. I suggest you do the things I mentioned above as these worked for me, you have nothing to lose :)
 
I see, ok thats great, I will do that and update then, one last thing, in addition to giving the +red to the blue/white wire of the red iso, do i also need to connect it with the blue/white (amp) wire coming from the stereo?
 
First try giving the AMP a good GND signal, after that try the blue/white to blue/white, if it still doesn't work, then connect the +12V red one as well, but I think the blue/white to blue/white should be able to do the job properly.
 
Also, if none of the above work, it might mean that you do not have the AMP at all (check for the subwoofer under the cloth trim on the left side of the boot when you open it). If that is the case, you need to wire purple and green wires to the LR and RR.
 

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It did not work, tried both way, gave ground also but no change.
 
Its audi a3 2006, i guess the amp comes built in it?
 
can you attach a picture where exactly shud i look for the amp?
 
Look for the subwoofer in the boot (it's a sign of amped system), it should be on the left as you open the boot, behind the boot trim. Here is a picture of how it looks like when you remove the trim.

PS: Attraction package models did not come with amped speakers.



S3SportbackInstallBosesub2.jpg
 
ok let me check, so if there is no amplifier then i give the signals to the green/purple wires i guess
 
Yes there is in amplifier in the boot.
 
On mine I just bypassed the oem wires completely as the power difference between the front speakers (headunit driven) and the rears (sub/amp driven) was too much of an issue, so just wired the speakers directly to the rear speaker output of the headunit
 
Here is photo of trunk.
 

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