Ammeter to Voltmeter...who does it?

Mattax said
I can't answer the questions about what came on it, and the differences.

I can, but only to a certain degree. Unfortunately, the MB300 is often overlooked in the Mopar Service Manual....the '74-'77 Parts Catalog is a better, but the people selling them online are very proud of them.

Mattax said
A higher output alternator will not increase the load on anything. It's the equipement that creates the load. The ignition, headlights, wipers, are only going to draw what they need. Or more precisely, the current flow through them will be limited by the internal resistance and the voltage across them. The resistance is fixed and the voltage is regulated.
Lets take a pair of headlights, nominally rated 60/55 Watts. At 12 Volts, 9 amps will pass through them. With the alternator running and regulated to 14 Volts, it could be 11 amps. Only 11 amps will flow through those wires regardless of the capacity of the alternator.

But having the correct Voltage Regulator matched to the alternator does play into whether you fry your electrical system, right? At least, this is what I've read, and this is where I get a bit confused, because the alternator is supposed to put out consistent voltage based on its RPM, so why would there be different Voltage Regulators? Do they also play a role in regulating amperage?

Mattax said
There is one item that doesn't have a fixed resistance, the battery. If the battery is low, it will suck more current at any given voltage. So this is the one circuit a higher output alternator potentially could fry connectors, and even the fusible link or at least weaken it....

With an alternator and the voltage regulated some other strategies need to be used. That's why I asked about the regulation of the coach battery charging and was speculating about the battery to battery connector with the smaller section wire.

And this is my concern, given that for 43 years it has had that Battery Isolator Charging Solenoid. As it stands, the Coach/House batteries (I actually have room for two) rely on the alternator to charge them and, since my electrical system is stock, I would need to continuously monitor their health, so that the chassis cab system isn't working overtime to maintain them, when I'm on the road.

Mattax said
Point here is not that a lower rated alternator is prefered. The above is an unusual situation. Rather this is an illustration of how the alternator output and battery charging relate.
In fact, under normal conditions, it is most desirable for an alternator to have enough power at idle speed to run everything at 14 Volts.
If it can't, then the battery must provide some. Then as rpms rise, the alternator has to recharge the battery. If this happens for hours on end, like stuck in traffic with A/C and lights on in 90 degree weather, the battery gets more and more drained, and when the car finally does move, the charging rate is high. The result is constant load, some of it high, on the fusible link, connectors etc in the charging circuit.
In the 60s, this was probably not in the design scenario. Rather the only big drain would be starting, and then after starting the engine would be on fast idle, easily taking care of the normal recharge from a cold start.

So this is where thicker gauge wire relaxes the stress that the electrical system experiences. At a minimum, even if I don't change the existing wiring schematic on my chassis cab, it will definitely benefit from thicker gauge wires. I know my first plan of attack will be thicker and added ground wires in the engine compartment. The guys on the Jeep Forum who preach thicker gauge and added ground wires under the hood. I figure if it's a good idea for the old AMC, it's probably a good idea for the old Dodge too.