My brother in law has an old 169A spot welder he acquired some years back when a department closed down. He remembers that it was plugged into a 13 amp wall socket. The problem we have is that the mains lead from the timer unit had the plug removed and there are 4 wires in the lead. Does anybody have any idea how this should be wired into a plug? This will give an opportunity to get this going wih my mini body panels.