I have an 04 Mondeo Ghia with Sony 6cd radio. I found the Aux input socket in glovebox,(plugged in Ipod)- but when I select "CD/AUX" button, nothing happens - it stays in CD mode only. Any ideas?
Try the 'hidden' menu, hold down the menu button for a few seconds and then you should find another menu to scroll down, where you should find an Aux on/off option.
Good luck