This may be a moot point or your question does not need an answer since a new harness is going in.... but....without reading all your posts to see what you have done:
1. I see you have a 350 installed.
2. A "brown wire" or brown wires, tells us nothing about where each end goes. Colors get changed and if you have installed an alternator, we don't know what the brown wire does. There is a sensing wire and a exciter wire.
3. Don't understand this: "the brown wire going to/from the accessory ignition terminal on the ignition" .
4. Like I said, does not matter now probably. Keep in mind for future questions. Wiring is a very specific item. It has "to-from" as it is called. Each "TO" and each "FROM" must be fully identified by it's component and the components terminal number or name. I.E. Ignition switch ACC terminal.
5. Consider buying a universal pre-wired fuse panel type harness. The ones where you mount the fuse panel on the inside of cab, on the upper left hood hinge bolts. Take out all wiring intact if you can. Take off all firewall fuse blocks. Don't throw any of it away. Removing the steering wheel is a good thing to do. The overall process is a great DIY project. I've done many TF's. Don't know what electrical gauges you have. The harness kits don't support ammeters, so dump it.Adding grounds? The wires fried because something got grounded. Your grounds seem OK
