Where do i find the pin connections to add rear speakers to a Ford 6000 cd ?

I am adding an amplifier to my 2010 For transit connect XLT and noticed their are pin confections on the back of he radio but they don't have any wires going thru the the harness connector, Does anyone know where i can locate these pin connection so that i may add wires to the harness. Or an adapter to wire in the amp?