Dash Power Feed Confusion
Well post more pics of what is there and do some continuity checks before hooking the battery up.
Especially this
There is 1 brown larger wire running from the alternator output and is welded to both of those smaller brown connections up near where they enter through the firewall.
Sure want the main power feeds connected properly!
Also if the car has an alternator alternator that uses a non-standard regulator and wiring, it would be good to know that sooner than later.
The diagram I drew only based on what I can figure from what you've posted and the various versions I'm aware of.
The other wires on the black ammeter side run to somewhere under the dash, possibly fuse panel, but I havent investigated at this point.
So it is a third connection!?
One possibility is rear window defroster. Was this car so equiped?
Another possibility is that it runs to the main splice.
I suppose it is also possible to run to the fuse box - perhaps for a dedicated fuse for something.
Finally, look for another fusible link on the battery line, possibly near the starter relay. It likely will not be blue, but probably has a flag on it.
Continuity checks. This is a method of figuring out what connects.
Disconnect the wires at the connectors of interest. Then measure for continuity from one terminal to where you think the other end of the wire connects.