Today I have attempted to install my Nokia ck-200 into my signums ccr2006

I have managed to get it all working except the phone sounds only come through the speakers when the radio is switched off.

If the radio is on the nothing can be heard from the Bluetooth system.

The Nokia cable offers the choice of 3 mutes.

Mute 1 & 2 - no sound from radio at all

Mute 3 - the radio works. So does the hands free if the radio is off.

Does anyone know this setup?

What can I do to sort it out?