1976 aspen Heavy duty charging questions

[Voeltagear]

Does anybody have one of the 1976 fleet vehicles with heavy duty charging? I have questions about the wiring schematics. Mine doesn't have a connector in the bulkhead. All the wires run through the firewall in a rubber boot then split off. There is a large connector under the dash with a screw in the middle for the majority of the wires. (I did inspect it and all the connections are clean without evidence of heat damage) The alternator wire appears to be 6 or 8ga and runs directly to the fusible link then to the battery. I also have the field and load relay which has 2 large wires for source and load and 2 small wires for the coil side. Additionally there is an orange box on the firewall that I don't see on the schematics. It looks like a voltage regulator with a different plug. It has 3 wires, blue, brown and grey. Blue and brown go to the field and load relay not sure where the grey wire goes. Anyone seen or worked on one like this? I'm planning an auxiliary fuse and relay box for an electric cooling fan, the headlights, ignition, voltage regulator, auxiliary charging port and stereo.

For reference it is a 4 door 1976 Dodge Aspen, 318, 4 speed. Custom trim level.

 

[Mikes5thAve]

I'm not familiar with that setup. Is the screw under the dash a ground or is it isolated and actual power?
One of my cars has one of these 12v circuit breakers added feeding a small fuse strip and equipment. If I was adding what you are I would probably come off the battery with a new feed and go that route. I like the setup being able to quickly shut off the power, circuit breaker wise I'm not sure how quickly it reacts.

Does that orange box have a flat white plug? The 70s ones had a module for egr timer or emissions that sounds like that. I forget what the wiring colors were.

 

[Voeltagear]

Aha! EGR timer. Got it. Ok

As far as the plug under the dash, the screw just holds the 2 halves together.

I was considering the circuit breaker route. I'm planning to feed a 6 circuit fuse and relay box. Looking at other posts I was planning to feed it with a wire directly off the back of the alternator. (Circuit breaker protected) Except for the voltage regulator relay, that would be fed battery voltage.

I'm still not sure where the 2 large gauge wires go from the field and load relay. Everything seems to work as it is so it's probably best left alone.