Radio Wiring

[Conman]

I don't know this info off hand but it is easy to find those three wires with a volt meter

with the meter on ohms put one lead on a bolt or screw that is grounded and start probing wires, when the resistance goes to zero you've found ground

next put the meter on dc volts and put the black lead on the bolt ground or the wire you've found and prob the other ones, when you get voltage there's power.

next turn the key to accessory and prob wires like the power one
remeber when you do this that you will also get voltage through the wires that always have voltage so when you think you've found one turn the key off and make sure the voltage disappears
so it is only live when the key is on and there is your third wire