Aftermarket stereo - how to get rear speakers working?

[mmarks]

hi all,

Did a search but couldn't find an answer.
I have a 2000 A6 2.4 petrol with the concert cassette radio and a changer in the boot.
I wanted to replace the stock radio as I have a radio with bluetooth so I can listen to my music from my phone & legally answer phone calls. Had this unit installed in many previous cars - all with no problem.
I bought the harness adapter from Halfords and fitted the head unit. Only took a few minutes but I have no sound from the rear speakers, only front.
I did read some posts that talk about the rear speakers being amplified.
My question is, is there an easy or step by step guide to getting it working?
My alternative is to install a parrot system for the bluetooth and calls which would connect to the stock stereo but I assume, as it goes between the harness and the radio, it too will only power the front speakers. I don't want to spend any more money if possible, I'm hoping there is a simple additional wire to connect.

Hope someone has done this before and can help.

Mike

[Peter D]

Remove the drivers side panel in the boot and look in and up, can you see an amp, I suspect you will. It sounds as if your adaptor cable has not routed the line out to the rear amp Tell me what model car you have and your email address and I'll send you the diagrams. Regards Peter