head unit connection woes

Hello Folks

has anyone here successfully connected a pioneer head unit ( i have a pioneer avicx1) to the offboard power amp in the octavia 2 ( with 12 speaker upgrade). I am having difficulty tracking down a lead that will link the two together. Autoleads did send one out to the fitter trying to do thsi for me but the ( at any rate first rev) autoleads lead did not work. Can anyone recommend a lead for this application?

thanks in advance

dod