I have a used 330 Magnum, runs fine. It began failing to crank (starter relay) and I purchased one online. I installed it one wire at a time to ensure the wires were correct. When I tried to connect the ground wire to the battery, it began cranking the engine, and the key was in the off position. It is unknown if the prior owner had done some sort of wiring shortcut and I have been unsuccessful at finding the wiring diagrams.