Hello guys, I’m standing in front of a big puzzle. Have a system ( Pioneer 3200BT,Dietz adapter 66030 and the vehicle specific plug etc for it ) from a 2005 he bought Grand Cherokee used. It should be built into a 2005 he Grand Cherokee !! So actually plug and play. As far as everything works well, steering wheel remote control and also the music plays over all speakers back and front ! But… I turn the fader forward, all the speakers go out, I turn to the rear, all play again !! Have test way the system in a 2006 he with Boston sound system and have the same effect !! So it seems that it doesn’t matter which sound system is installed. The previous owner of the radio swears that everything has worked with it… Without vehicle specific adapter everything works on the radio as it should, back and front are separated and allow itself to thread. According to the circuit plan of the original cabling of the Jeep and the Dietz adapter everything fits, it’s not twisted or missing… With the original radio funts also wonderful.