I have a 2004 Dyt4000 Craftsman Riding Lawn mower Model# 917.273620. When I replaced the battery, I bought the wrong battery where the positive and negitive are on opposite sides than my original battery. I didn't notice this until I started the mower and heard the grinding noise. I found the 20amp fuse that was blown. After replacing that, I discovered it shorted out the PTO switch. I replaced the PTO switch. Still the blades would not engage. I cleaned all the wire plugs with air. I started the mower and pulled the PTO switch and the blades started working. When I stopped the blades and shut off the engine, the engine would not start again. I checked the fuse and it was blown. If I replace the fuse, it will all work until I shut it off again. Does anyone know where the short can be? Can it be the clutch? If so, is it something that I can change out myself?