Does my MF135 generator need an external voltage regulat

Greetings,

I hope my "newbie post" won't reveal too much ignorance, but, I'm trying to understand wires on a 1971 MF135 Deluxe that suddenly wouldn't start. This machine started life with a generator, replaced sometime in the past with an alternator, and that's the part I'm stuck on. I tried Search on "alternator", but it would've taken about a week to read every single post, so here I am, hat in hand, hoping you won't thrash me if this subject was discussed already somewhere else.

My question is this: Can anyone tell easily from my photo whether this Delco-Remy alternator has a built-in voltage regulator? It's confusing because the 4-pin "F 2 3 4" VR was still in place, right near the battery, but only the "F" and "3" wires were still attached to the 4-way connector that was plugged into the VR. The "2" and "4" wires had been cut, and the water temp and fuel level gauges removed. I'd like to replace those, but I can't make much sense of wiring diagrams because every one I've seen is so small that their smallest print re the VR terminals is unreadable. Bottom line -- I don't want to try to hook up an alternator to an external VR if it already has one, as you can well imagine.

As the picture shows, there's only one wire bundle attached to the alternator. I've labelled that "A". "A" has two wires, plus a third that's been cut. "A" seems to be electrically isolated, so I think that's where the generator fuse is. There's a ground wire nearby, disconnected, that also has a wire that's been cut, and I suspect those two cut wires were once joined. The alternator has no part number on it. That's long gone. It just has "BAT" on the back in raised letters near "A". Plus, it has "R", "R", and "F" near the top, positioned as shown by the yellow arrows.

Any help here would be most appreciated. And, I do apologize if this topic has already been discussed.
mvphoto93851.jpg
 
(quoted from post at 23:30:10 06/29/22) That is a one wire Delco with internal regulator. It does not use an external regulator

Many thanks. I really appreciate your help on this.

So, I should be able to just ignore the voltage regulator shown in the standard wiring diagram, and treat the alternator output, rather than the battery, as the direct 12V power source for all gauges, correct? That should result in gauges being turned off when the engine's not running.
 

The Battery terminal on the alternator always has battery power, unless you use a disconnect switch or unhook the battery. The battery wire from the alternator should go directly to the same terminal of the ammeter as the loads (like the ignition switch, light switch, etc.) You may need to repower the fuel gauge directly from the ignition terminal of the ignition switch for the gas engine or oil pressure switch on a diesel, as it looks like it was powered from the external regulator in a 135 electrical diagram I have. It appears the oil pressure, temperature and tach are mechanical gauges in the drawing I have, the wire shown going to them appears to be for lighting.

Gas and diesel may be different as the diesels often used just a switch to engage the starter. The gauges and other electrical, that needed to be switched on and off, was connected to an oil pressure switch mounted in the dash behind the oil pressure gauge.
 

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