sound system help

Hi can anyone help me?

I have just installed a pioneer head unit and 12 disc changer in my Mk 1 cabby.

It works fine through the original speakers but as soon as I try to fire up an amp (on a kill switch) there is a VERY loud whine which varies with the revs and a banging which coincides with the popping I have from my exhaust.

I have the power cable and the phono cable running mid air and well away from each other and to ensure a good grounding have drilled a small hole into the cross strut behind the back seat

I originally wired up two amps (my old one and a new one) now I have just my old amp connected exactly the same as was in my E reg mk2 and still no joy.

I have tried everything I can think of and the only thing that I can see is that I may need a suppressor (which no one seems to have).  

Any Help much appreciated
Craig   :dontknow:

This thread might give you a couple of pointers - http://www.vwgolfmk1.org.uk/modules.php?name=Forums&file=viewtopic&t=20713&start=10&postdays=0&postorder=asc&highlight=