Hello chaps need some help with alternator/ electrical noise over my radio/cd. With the engine running i've got a whine,even with the sound turned right down.With the engine off,but ignition on i've got noise from the throttle,door switches and window switches. I've tried a suppressor on the alternator to no avail,is it afaulty earth ,if so where? The radio is the "CONCERT" unit in a 2000 1.8t se quattro. Any help gratfully received.