Not sure if I will get a reply considering how old this topic is, but I have the same unit and it did not come with an alternator. I was hoping that someone could tell me what size alternator that should be used for it? I have a scout II and am hoping to set it up with the welder. I have called up premier power welder and they could not give me any information on it and I have looked up other forums. The most I can find out is that its either a 160a or 190a alternator... but then again I have also seen 110a.