Aftermarket head unit installation with PC9-404 no power

[Joe Morgan]

I've recently purchased a 1999 Audi A4 Avant. The previous owner had wired in a Sony aftermarket radio in replacement of the Audi Concert, however only the front 2 speakers were working. After reading through this forum I concluded that I needed to buy a PC9-404, allowing me to use the RCA connectors on the rear of the radio.

I purchased this adaptor from Halfords - http://www.halfords.com/technology/...pc9-404-pc9-410-audi-iso-lead-harness-adaptor

The image below shows the rear side of the radio with the Sony loom:

The image below shows the PC9-404 (and PC9-410?) adaptors (notice the 'ignition' wire):

The image below shows the connectors inside the console (the brown connector has 4 wires in the center, which I think I'm right in saying means I have a 1/2 amplified non-bose system).

The image below shows how I've connected the two adaptors. The PC9-404 (I think) on the left, and the PC9-410 on the right.

I've then attached them to the head unit, as so:

And have managed to wiggle in (without splicing, yet) the ignition cable into the 12v cig lighter:

The problem is that I now have no power going to the radio, even with the ignition turned on. My thoughts on what could be wrong as as follows:

1. I need to properly splice the ignition/+12v cig wire together (which is going to be a lot harder than I first thought) - unless there is another 12v switched source I can use?
2. The blue/white wires are needed for something (after reading through many many forum posts I still haven't quite worked out what they're used for)
3. I've done the entire thing wrong...

If anyone can shed some light on my situation that would be great. I just want to have all 4 speakers working in my car, really didn't think it would be this much hassle...

 

[aragorn]

you dont need the 410, (the bit on the right) Just put it back to how it was, and add the 404 to the RCA sockets.

 

[Joe Morgan]

Hi aragorn,

Thanks for the reply. I've tried that. I get power now, but no rear speakers still.

Any thoughts?

 

[aragorn]

there should be a blue wire from the 404? That needs connected to the blue wire from the radio, the one with the bit of tape on it.

 

[Joe Morgan]

Okay, yep. Which end of the blue wire coming from the radio? Shall I undo the tape, split the two wires and connected the 404 wire to the wire coming from the back of the radio?

 

[Joe Morgan]

Okay, I've spliced that wire in. When setting the balance to be completely at the rear, I'm now getting a very low bass from the speakers but nothing else, and it's very faint unless turned up very loudly.

 

[Oranoco]

Check the head unit doesn't have the pre-out set to sub.

Swap the RCA plugs to the front outputs and see if it still behaves the same way

 

[Joe Morgan]

Thanks Oranoco. Have swapped RCAs, same problem/no sound at all.

I can change the settings from 'Sub out' to 'Rear out', but the audio is still quiet and over bassy.

 

[aragorn]

Avant models have a small subwoofer in the rear side of the boot, and then the two rear door speakers.

The head unit sends the pre-out to the subwoofer unit, which has a small amplifier which drives all three speakers.

If your just getting bass, it suggests the subwoofer is working but the door speakers arent for some reason?

 

[Joe Morgan]

avant

 

[aragorn]

sorry i edited my post as you'd said avant in the first one!

 

[Joe Morgan]

apologies! Thanks for clearing that up! There is some sound coming from the rear speakers, but it's very very muffled, quiet and bassy, and is only noticeable when I direct all of the sound to the rear speakers via the head unit. At a bit of a loss with this one now...

 

[aragorn]

Well i would suggest seperating it out into two seperate systems and test each.

Get an ipod or similar, and connect the RCAs to the ipod and see if the rear speakers work.

Then get an amplified speaker and connect it to the head unit and see if the line outs work.

 

[Joe Morgan]

Thanks for the reply and sorry mine's so late! I'll give that a go when I can, just means buying cables etc. to test, thought it would a bit more straightforward to get all 4 speakers working... Nevermind!

 

[aragorn]

it usually is just a case of plugging in and off it goes.

 

[Joe Morgan]

I've just spent another hour in the car and started from scratch. Not sure what I did differently but *** 4 speakers and the sub are now working! Thanks for the help everyone, much appreciated!