Wisconsin AC4 Service Manual. Written in the language of a mechanic, this Service Manual for Wisconsin provides detailed information on how to take your Engine apart, fix it, and put it back together. You will need this manual if your Wisconsin is broken. Also known as the Repair, Shop, Technical, IT, Overhaul manual. This is a 58 page factory written reproduction service manual and would have been given to the dealer service shops back when your equipment was new.