I have a Sony 6500 cd/md changer. It had been running on 2 front door speakers, untill yesterday when I wired in a set of 6*9's on the parcel shelf. This was all working fine this morning and again when i used my car around lunchtime, but when I got in it tonight,i've got nothing-no sound at all! All the speakers are still wired in and I don't think it's the stereo/head unit as i've tested my mates stereo/head unit on the system and still no sound. Anyone got any ideas pleeeeease??