Im trying to get a Pioneer 1200MP head unit working in my B5 98.5 A4, i have bose amplified rear only. I've got the headunit working perfectly in all but the rear speakers. I purchased the Autoleads adapter PC9-404 to try and get the rears working, i cant work out where the blue and white lead should go to enable the amp, if i connect it to a 12v feed (same one as the aerial adapter) i get the rears working for 2 seconds then they go off. Turn the stereo off and on and again they work for 2 seconds then off. Any ideas?