Hi everyone,


Apologies as this post will be a bit vague to start with as I haven't seen the car.


One of my friends has installed a new multimedia head unit into his Audi A3.


Now (hopefully) he's bought a wiring harness adaptor, if not this job may become more difficult!


I understand that everything works fine but he is unable to hear any music from the rear speakers. Upon contacting the head unit manufacturer they have advised him he needs to get a remote signal to the factory amplifier in the boot.


Can anyone point me in the direction of a wiring diagram or colour codes that may help me identify the remote wire on the factory amp?


If not I may just reinstall the original head unit and use a voltmeter to determine which wire the remote is at the amp side of things (which is what I'd do if I was doing the install).


If I get any more information I'll post it up here but I work a daytime job as well as in the evening one so spare time is a bit tricky!


Thanks in advance