I've got an issue with my 2003 BMW 330 coupe which has the optional harman kardon stereo upgrade fitted.
I understand that there is a seperate amp in the boot with this upgrade,
I'm experiencing a annoying issue where there is a constant static noise whilst the player is on quietly or even off. If the ignition is not on, there is no interference it's only when the ignition on. Head unit (standard) on or off makes no difference.
Any ideas as to how I can reduce or get rid of this interference ? Driving me mad! It doesn't increase with volume by the way so gets drowned out with loud music