Whatever that black box is I havnt figured that out yet. The pos. wire comes directly from the starter, which is a junction directly from the battery. The other side reads to ground and that might be my problem. It goes through the key switch and that is where I stopped my tracing. I will start there tomorrow. The 30 VDC could be a bad regulator and might have melted that run of wire.
Now where to get a new regulator?? Where is it mounted on the tractor?? Just under the hood, just above the fuel tank, is a little black box with a light on it that glows red when the tractor is running. Has 3 wires going to it. Could that be the regulator/rectifier??