Smoked fusible link and ground wire
This is another simplified diagram showing why I'm asking about the switch position when it was OK and when it grounded out.
When you look at a factory diagram, the wires from the run position feeding the alternator field and ignition are labled ignition and have an identifier starting with J. The wire from the ignition switch to the fuse box is called accessory even though we may not think of those things that draw power from it as accessories. The accessory wire can also be powered alone from the accessory postion.
In Start a different set of wires gets power.