ok unfortunatly ford decided that there sort of colour code is just not normal resulting in DIY testing

there is some sort of uniform though
3 of the speakers are

posotive wire to the speakers is yellow/black
negative wire to the speakers is white/black

with the white n yellow of the wires bein the main colour with a strip of black on them

then it say's right side rear speaker

posotive = yellow/red
negative = white/red

honestly don't ask lol but aslong as u keep the posotives n negatives the same n just find out by trial n error witch are the other three speakers by changing the balance n fader on your unit,

they do run in order on the original ford connector block if it's still there, that's the longish yellow one if i can remem, if u can read the numbers on the one side of the con block itself then the wires goin into the corresponding terminals are

front left speaker is #1/2
front right #5/6
back left #3/4
back right #7/8

i'm sure that's right but let us no if u have n e prob's

oh yea n if u can be arsed i would go to halfords n buy an iso block n connect that up instead u should have an iso connector with you stereo so if u ever want to chage unit again it's plug n play