Help with 100 Amp Diagram

[ODRotorHead]

I left the 100 Amp inset off the M151A2 electrical diagram to reduce clutter. I don't know how many (what percentage) of the systems out there have 100 Amp generators, but I didn't want to leave anybody out so I worked up a separate 100 Amp diagram.

The diagram is essentially a copy of the original, but there's something on the original that doesn't seem quite right. My system is 60 Amp, so I can't check it against my MUTT. I'm asking someone/anyone who has a better understanding of the 100 Amp system to check on this and let me know if the original diagram is correct.

Here's a draft version of the diagram:

M151A2 100 Amp Gen Diagram 005A.jpg

The wires between the generator and the voltage regulator (B to D, and D to B) don't match up, but I don't know if that's correct.

Original diagram from TM 9-2320-218-20-1-2 (MAY 82):

M151A2 100 Amp Generator Diagram 001A.jpg

New diagram:

M151A2 100 Amp Gen Diagram 005A1.jpg

The original (and new) diagram has . . .

GENERATOR......REGULATOR
......B . . . . . . . . . > D
......C . . . . . . . . . > C
......D . . . . . . . . . > B
......E . . . . . . . . . > E

Are the B and D terminal designations on the voltage regulator reversed ? ? ? ? Please let me know.

Once I know for sure how the terminals should be labeled, I'll make any required corrections and post a clean copy.

Thanks for your help.

Mark

[rickf]

Go here and download the PAM75 manual. That may give you some insight.

https://radionerds.com/index.php/File:D ... 750-33.pdf

[rickf]

I looked at a different manual and it has different pics but wiring is the same. Top of page 3-29.

/https://www.steelsoldiers.com/upload/M1 ... 218-20.pdf

[Horst]

my 151, when converted to a MRC-83A radio jeep by the USMC, had the 100A alternator. But that was removed when they also removed the radios and mounts before that batch of Barstow 151 was sold off by the DRMO.

I would think there are very very few 151 with that setup out there

[muttguru]

Here's a scan of page-5 from TB9-2320-218-20/2 dated 22-Mar-1962: 100-Amp Generator Kit.
Unfortunately I don't have access to any later version of the TB but as you can see, the connections look straightforward enough.

Click on the diagram for a bigger picture.

Ken

[rickf]

Ken, I think the difference here is going to be that the 1962 setup will definitely be a generator where the A2 setup is more than likely an alternator and therefore the rectifier will not be in the picture. In the alternator is is built in.

[muttguru]

Hello Rick,

from what I gather from the TM9-2320-20-1-1 (1982), there is indeed a separate regulator even though there is an alternator.

If you look at that TM, page 11-191 through to 11-195 you will see it described.

In TB9-2920-225-34-1 dated 10-Nov-1981 (100-Amp Regulator: Checkout and Repair Procedure): you can see the regulator completely separate
from the Alternator.The regulator itself also has a voltage regulator access plug with a screw-adjust rheostat inside.

Ken

[Horst]

In the 151 and the 100 amps setup the washer reservoir is relocated to the driver side to make room.

[rickf]

Hello Rick,

from what I gather from the TM9-2320-20-1-1 (1982), there is indeed a separate regulator even though there is an alternator.

If you look at that TM, page 11-191 through to 11-195 you will see it described.

In TB9-2920-225-34-1 dated 10-Nov-1981 (100-Amp Regulator: Checkout and Repair Procedure): you can see the regulator completely separate
from the Alternator.The regulator itself also has a voltage regulator access plug with a screw-adjust rheostat inside.

Ken

Yes Ken, it does. But also note that the wiring for that system is as Mark shows in his diagrams. With what looks like the wires reversed. If you look at the actual internal wiring of the regulator it will make more sense. I checked several later diagrams for different vehicles using that system and the wiring was always the same. As Horst says, the 100 amp system puts the regulator on the passenger side fender. The 180 amp system puts it there also but it is cooled by the vehicles cooling system.

[ODRotorHead]

Thank you for your help and advice. When I asked, I thought it would be a simple matter of someone going out to the garage to check the 100 Amp system wiring, but it turned out to be more complicated than that. I looked back through earlier versions of the TMs, and every diagram I found showed the same wiring configuration (thanks muttguru):

-20 100 AMP GEN ELEC DIA 001B Low.jpg

I still don't understand why the B and D wires are "crisscrossed," but if it was a printing error, it probably would have been corrected long ago.

The -20 from SEP 71 includes a sketch of the 100 Amp Alternator as it connects to the Regulator. The sketch shows a connecting cable with circular connectors on both ends:

-20 SEP 71 - 100 AMP GEN 002B.jpg

Circular Connector - 4 Pin 001.jpg

Assuming the sketch is accurate, there's no possible way to "miswire" the two components. Since circular connectors are "keyed," the only possibility of a wiring error would be a cable/connector that was assembled incorrectly during manufacture. While that is a possibility, it's highly unlikely.

So . . . I'll post a finished version of the 100 Ampere wiring diagram as is:

M151A2 100 Amp Gen Diagram 005B.jpg

Side note: During my research, I learned that there are four generator/alternator output options - 25 Amp, 60 Amp, 100 Amp, and 180 Amp. I'd never heard of the 180 Amp generator. I'm guessing it's pretty rare because it's intended for use with the Xenon Searchlight.

Thanks Rick. The 750-33 pamphlet you recommended is outstanding.

[rickf]

I have never seen the diagram for the 180 amp but I did see a complete setup years ago at the Gilbert show. There was a guy named Carl that used to set up right inside the gate to the left as you came in and he had all kinds of interesting M-151 stuff. Including a couple of complete searchlight mutts. One of them had the 180 amp setup. I went over that thing for an hour trying to wrap my head around it.

[ODRotorHead]

180 Amp System Information 001.jpg

[rickf]

I am guessing you have already searched for those two manuals?