Audio adapter - interference

[hubrad]

Hi all,

I've got one of those Connects 2 adapters, so as to use my phone as satnav/music player via the existing stereo.

This adapter tricks the stereo into thinking it's a CD changer, so the audio inputs work. Does the job nicely, and the steering wheel controls aren't affected.

The problemette I'm having is some kind of interference. All's fine until I plug the phone charger in, then it's a bit of a whiny/staticy background noise which is just audible enough to be annoying from time to time.

I've tried a couple of different USB chargers, so pretty sure it's not just a faulty one of those.

in my mind, I'm thinking either some kind of earth loop or unevenness in the +ve supply.

I see that on the 2006 Corolla the radio is on a different fuse to the cig lighter socket - possible clash there?

Has anyone come across this before, so as to save me going in at random?