Burnt wire

ajarofclay said
I had to dig through some boxes and found an old manual on CD.

If that works. Lets use it. Otehrwise you can download one from mymopar.com

ajarofclay said
From what I see that terminal should only have one wire going into it. I chased where that wire goes to and found it basically splits between a ground and the ignition switch in the interior and then under the hood going to the ballast, alternator Etc

Nothing should be grounded!
Ignition switch going to ballast, alternator field, etc is the Run circuit. In the shop manual the run circuit wires are identified as J2. Branches and segments are J2A, J2B etc. The - Wire gage and color.

For the bulkhead connectors, there is a photo in the Plymouth shop manual. That will help with orientation when looking at the car for real. Note on the engine side each connector a bump out to further help with orientation.

So I think you are looking at position N.

I'm on a laptop with somewhat limited internet now.
So check out this post for a what I think is the '72 diagram which does show J2 going to N.
Cavity P has the alternator output R6-12gage Black. That is hot. Connected to the battery positive.
Position J should have the fusible link. Be careful with both of those.

I would look at the fusebox for an accessory slot that can be used for the A/C. That's what the factory did for A/C power in the 60s. Not sure about later.

But first get your J2 circuit squared away. Its a critical circuit. Too much load on it and the regulator will see low voltage due to resistance. It will correct causing the alternator to output at higher voltage than it really should be. This cooks the battery.