If you look CLOSELY on the wiring from the alpine connection to the join into the loom,it SHOULD tell you what each wire is for,,
on the sony lead that im looking at just now it goes:(on Power plug 4 wires )
black is earth
red is power
yellow is switched power
blue is antenna power up
(on speaker plug 8 wires)
purple rear right +
purple/black rear right -
green-rear left +
green/black rear left -
white front left +
white/black front left -
grey front right+
grey/black front right-
blue/grey square trace for telephone mute
blue/white trace for amp on
think thats it,hope it helps