The only head-unit was getting a little tired so out with the old and in with a new Bluetooth, USB & MP3 cd one.(Sony MEX-N5150BT) – the power is done, now to splice into the speaker loom. The last time I did this I was about 18 years old when I upgraded the factory stereo in my old Fiat Tipo, first attempt didn’t go so well and fried the unit, what could go wrong?!