This begs the question, why wire it directly to the battery so it can be operated with the key off, if you suggest having the machine running while using the winch?The wire you are referring to is the activation wire for the solinoid. I wire mine directly to the positive on the battery. This allows the winch to be operated without the key on. You need to be careful that someone does not operate the winch by playing with the switch though. Also make sure the engine is running when you operate the winch or you will be running the battery down in no time.