The inside door should indicate the correct polarity. I forget which is which, but there DC+ and DC- (or whatever, I forget). Anyway, it depends whether you are flux core welding or gas welding.
I see that you did buy it used, but hopefully the sicker on the inside of the door is intact. The chart on there should tell you the polarity.
Just wanted to give you a heads up in case you missed it.
I have a Lincoln 180C welder. I've been trying to teach myself for years now. LOL I just never have the time to play with it. Welding is a time consuming art. With all the cutting, grinding, cleaning, welding....Ain't nobody got time fo' dat!
