Wiring harness rear speakers help needed

[tcn]

Hi everyone- new here.

I'm hoping someone has an answer for me. You've probably had a variant of this question a few times. I need to know how I can use the amped speakers in the rear of my 96 a4. It's not the bose setup. I figured I wasn't gonna get rear audio when I saw the car's wiring harness was blank on the lr and rr slots.

So- there's a 3rd wiring harness- the one that attaches to the rear- cd changer, back speakers, etc- I didn't get a harness to plug into it in the dash kit i bought. I don't want to buy a new amp. I don't want to run speaker wire up to the head unit. I want to use the audi amp in the back with my aftermarket JVC deck.

Mainly what I'm looking for is what connections I need to make to that 3rd harness (the blue, green, yellow number) in order to get rear sound. Any help will keep me from having to wait 3-6 weeks for the other harness.

thank you!

[daren01]

Im having the same kind of problem - i got a fitting kit from halfords and its missing the rear speaker set up block - and i have tried looking for wiring diagrams - but i cant find anything to help - im lost too

[tcn]

at least i'm not alone. I'll let you know if i get an answer elsewhere!

[daren01]

You need to get a kit online that covers the whole set up - involving all the cables - halfords dont do it - but there easy to find - good luck

[Melchett]

Hi all 1st post so be gentle, I have just bought an A4 and it has this adapter connected to the aftermarket JVC stereo.



But there is still no sound from the rear speakers, what could I be doing wrong? The adapter was attached to the stereo when I bought the car so im not sure whether it is an amp problem, speaker problem or wiring problem.
The blue cable with the bullet connection is not connected to anything, could this be the answer?

[daren01]

I have the same problem i just got the pc9-404 kit looks the same as your picture and its not working for me - so i have emailed them to see if they can help me - i will let you know the outcome

[Melchett]

I have the same problem i just got the pc9-404 kit looks the same as your picture and its not working for me - so i have emailed them to see if they can help me - i will let you know the outcome

Cheers ears.

[tcn]

I have the same problem i just got the pc9-404 kit looks the same as your picture and its not working for me - so i have emailed them to see if they can help me - i will let you know the outcome

I don't know for sure, but Im guessing you need to get the 12 v into that red harness, to power the separate amp in the back. The red harness needs to get rigged with the l and r rear line-level output from the deck, usually facilitated by RCA connections.

If that harness you got came with a piece of paper to tell you what contact or wire does what, can you scan it and post the image?

[daren01]

I didn’t get any instructions with it - and they haven’t bothered to get back to me either

ok i think i have solved the problem, this cut and paste may help - it helped me

When installing Car Stereo Fitting Kits for Non-Bose systems, using PC9-401, PC9-408 or PC9-409, the lead needs to be adapted to allow switching on of the original fitted Amplifier.
All Audi's using these leads have active rear speakers, built into the speaker themselves. These adaptors convert the New head unit Speaker level output to line level output for the active speakers. These leads feed into the Red Mini ISO plug.
The blue & White wire on the Red mini ISO plug also needs to be connected to the Blue wire coming off of the New Head Unit (marked Amp Remote). At the same time the blue wire on the PC5-90 adaptor also needs connecting to the Blue wire off the New Head Unit.
To do this cut the blue wire between the two Black ISO connectors half way along. Plug the blue & white lead supplied with the red crimp connector on the end into the bullet connector from the Red Mini ISO plug.
Cut the blue wire from the PC5-90 half way along. After stripping, feed both the blue from the PC5-90, and the blue coming from black ISO connector which will plug into the New head unit (not the car end) into the Red Crimp connector. Crimp the connector using proper crimping tool.
Once complete both the PC5-90 and Red & White wire on the mini ISO connector should be getting +12V from the new head unit.
This will power the antenna adaptor and also signal the remote amplifier to switch on.
Also note if your new head unit has RCA outputs with an output above 2.2v, you could use PC9-404 or PC9-410. Installation is the same as above accept the RCA connectors replace the speaker connectors.
Beware that we have recently come across issues of slight interference when using PC9-410 with the latest high powered Alpine and Pioneer head units, in this case use PC9-408

When i attached the blue/white wire (supplied with the harness pc9-404 ) on to the blue wire from my stereo - and turned it on - behold sound from the rear speakers - it wasn't super loud - but it was better than nothing - i just wedged in the cable - see attached picture - i will play around with the settings and try to sort out the low sound from the rear

I will add more if i find out anything else