Actually, I was looking for a wiring diagram or a list of what each wire does. I'm installing an aftermarket rear window defrost and I need to tap a wire that gives enough current while the car is on, and none when the car is off, so the battery doesn't get drained.

What is the current draw of the defroster? I don't know of any wiring in that area designed to support a heavy load. You should run a power lead under the rear seat and carpeting, to the fusebox. Find a spare slot, and use it for your defroster. It should be on it's own circuit.