Hi all I am having problems fitting a new Kenwood headunit in my wifes 05 diesel picasso. Removed the non working Citroen oem unit to find one black and one white iso plugs, ok I thought this should be quite an easy fit. Power side was not an issue checked out 12 volt and switched 12 volt required swapping red and yellow wires on supplied Kenwood harness adapter. Unit powers on and off using key and shuts down on economy mode as normal. Speakers however; Wiring in manual against Kenwood wiring checked all matched (ISO) Connect white plug to Kenwood head unit - mis wiring check check wiring then power on message on head unit. Disconnect white plug - unit powers on/off and operates normally. Ok, I thought must be bad speaker or wiring fault, measured impedance at each speaker connection on plug 4.1 or 4.2 ohms on digital multimeter. Disconnected each speaker ( 4 speakers & two tweeters on dash) one at at a time same message each time. Ended up with all speakers disconnected same message when white plug connected. Dis connect plug unit operates normally. Checked all connections at plug with all speakers disconnected all open circuit so no short circuit and no short between each individual speaker. Tried resetting car BSI, made no difference to head unit & all dash functions are working trip economy computer etc.. I really do not know what else to try apart from biting the bullet and rewiring the whole car. Any advice would be much appreciated. Regards Steve