Voltage Regulator problem
So you know what you're looking at here.
Wires are coded with function, wire segment, the wire gage and insulation color(s)
For example A indicates battery related, and S is starter related.
Here's teh snip from the wiring diragram so you can see how it works.
+A green S4 was used on manual transmissoin cars.
You can download the '73 Dodge chassis manual which has these diagrams.
This is just to get you started.
The '73 diagram can be a bit difficult to work with. Nothing wrong with redrawing or electronicly tracing or highlighting.
The basic scheme is sometimes easier to understand when laid out more in the manner of the earlier diagrams.
I don't show all of the specifics, but you can modify based on the shop manual and what you find.