Are you trying to wire in a factory? Because if not, you don't really need a factory harness if your going aftermarket with your stereo and speakers.

Just find the proper sources as it describes in the stereo's instructions.

My son has a tremendous sounding Sony Explode in our 82, with Sony Explode speakers in the front doors and big 10" or 12" speakers and little ones in boxes behind the seat.

We just ran our own wires. You just need a ground, constant power, and switched power, and amp wires if you go that route, then your speaker wires.