65amp wiring/trouble shooting

I have done some research on my wiring as showed below, starting on the starter relay.
starter_relay.jpg

fusible link.jpg

ammeter_cable.jpg

bulkhead_connector.jpg

funny_green_box.jpg
Three connectors and heavy wiring. Likely a heavy duty system. Lets figure it out.
Begining at the battery. Red wire (A1) goes to the starter relay shown here.

View attachment 1716023035
We see a junction here with two other wires. One large red wire and the other a black? fusible link.

Next.
View attachment 1716023029

View attachment 1716023032
Not what we are seeing here a the grommet - Other than its probably to the ammeter. Will come back to this.
We also see a red wire to a connector possibly going to the multiconnector.
View attachment 1716023033
Looking at this one we see another red wire and connector that may be going into the multiconnector.

Do you have a picture of the original voltage regulator and connections?

Let me get my dinner cooking and will come back in bit.