iPod whistling noise that follows engine revs

[miniman]

I recently fitted a Connects2 iPod adapter to my Discovery. It plays music fine however when using it, there's an annoying whistle in the background. It is most noticeable during quiet / silent sections (e.g. the lead in to a quiet track) when it is very annoying indeed. It increases in pitch as the engine revs increase.

Any advice on noise suppression, ground loop thingumtys and suchlike greatly appreciated!

[andy-xr]

It used to be the case with tape players/headunits etc that it wasn't earthed properly, but I'm guessing you're plugging into an existing connector?

[miniman]

Yes it intercepts the wiring for the CD changer but worth checking all the connections I guess.