Ammeter to Voltmeter...who does it?

Not quite. Now its back stock. Which IMO may be fine - everything you show looks pretty heavy duty and clean (except the crunchy fusible liunk)
(Edit: yes like in the post above. You got it! No need to lengthen or cut anything, just add one wire with link. You can keep or the ammeter or not, it just won't read the battery charging. It probably will read the battery discharging at start. That's what mopartim observed. Probably 'cause its the shortest route to the main splice from the battery.)...

So, final electrical schematic design, and it looks like we have a winner. My Dad was an electrical engineer at Westinghouse, and he taught me enough to be dangerous, LOL!

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m3zZPvb.pngClick For Full-Size Image.