Re-Wiring 1975 Plymouth Duster

Even when you get the FSM, it'll take some studying to decipher and learn it. It was intended for professionals who worked on this stuff daily, so it can be a bit daunting at first. It's well worth your time to study it, preferably near the car so you can reference between the two. Once you've got a decent grasp on it, you'll figure out pretty quickly what's been hacked, and how to repair it.