What is this 14 volt alternator terminal for?

[Woodsplinter]

I recently discovered there is a terminal on the alternator of my A2 deuce that puts out 14 volts. It is next to the 28 volt terminal that is connected to the starter solenoid.

Does anybody know what it's for and can it be used to supply 12 volts to accessories like CB radio, cell phone charger, etc.?

Thanks!

 

[rustystud]

Now that's interesting. I wonder is something has gone bad inside there. I guess I'll be doing some reading tonight.

 

[Woodsplinter]

Now that's interesting. I wonder is something has gone bad inside there. I guess I'll be doing some reading tonight.

I don't think anything is wrong- I was clued in to this possibility by a friend. He said he was surfing the net for deuce info and found something (he thought it was Wikipedia), that stated that deuce alternators made after 1980 had dual voltage capability. I was unable to find what he was referring to. I decided to check it out with a meter and sure enough, this terminal puts out 14 volts.

I have never heard any reference to this before so I'm mystified.

 

[clinto]

There are dual voltage alternators, originally for HMMWVs in 100A flavor and later on, in 200A and 400A varieties for MRAPs and such but the alternator pictured is the standard M-series 60A 24V unit.

I do not understand why there is 14V at that stud.

I have never seen any piece of military literature (TM, PS magazine, etc.) that referred to post-1980 alternators as being dual voltage.

 

[Keith_J]

Probably field voltage off the regulator that goes to the brushes. See what it does when you put a load on the alternator, like turn the high beams on. If it increases, then it is field. I would NOT recommend putting any load on it as it would cause issues on stability of the 28 volt side.

 

[glassk]

Now that's interesting. I wonder is something has gone bad inside there. I guess I'll be doing some reading tonight.

Split-Series Field Generators (Fig. 13-17
a. Generator regulation sometimes is accomplished by
means of a split-series field. A generator with this
method of regulation combines third-brush, reversed series
(differential), and cumulative-compound
principles.






TM 9-8000

http://www.liberatedmanuals.com/TM-9-8000.pdf

 

[oddshot]

I recently discovered there is a terminal on the alternator of my A2 deuce that puts out 14 volts. It is next to the 28 volt terminal that is connected to the starter solenoid.

It might be useful to identify what alternator you have.

Are there any id tags, labels or manufacturer number stamped into the alternator anywhere?

 

[Woodsplinter]

Probably field voltage off the regulator that goes to the brushes. See what it does when you put a load on the alternator, like turn the high beams on. If it increases, then it is field. I would NOT recommend putting any load on it as it would cause issues on stability of the 28 volt side.

I put a load on it and the voltage increased from 14.25 to 14.39 volts.

 

[Woodsplinter]

It might be useful to identify what alternator you have.

Are there any id tags, labels or manufacturer number stamped into the alternator anywhere?

It is a Leece-Neville alternator, 60 amp. Couldn't read anything else on the tag but like Clinto said it is the same as on any other deuce I have seen.

 

[Woodsplinter]

Well, not sure what its for but I don't intend to use it for anything. Thanks for all the input!

I'll just close it up and continue on...

 

[rustystud]

I put a load on it and the voltage increased from 14.25 to 14.39 volts.

Yep, field voltage.

 

[Mayapple]

I recently discovered there is a terminal on the alternator of my A2 deuce that puts out 14 volts. It is next to the 28 volt terminal that is connected to the starter solenoid.

Does anybody know what it's for and can it be used to supply 12 volts to accessories like CB radio, cell phone charger, etc.?

Thanks!

View attachment 553785

What voltage does the black plug need to be, and what does it go to? Trying to figure out my alternator swap before I put power to it and destroy anything.

 

[LiveFreeOrDieTryn2B]

You need to post pics of the wire your referring also if you had a dual voltage you could run 3 batteries I did it and its one of the best upgrades I have done.

 

[Mayapple]

You need to post pics of the wire your referring also if you had a dual voltage you could run 3 batteries I did it and its one of the best upgrades I have done.

the black male/female plug wire. Schematics say it goes to starter relay. I'm guessing that's the ignition side of the regulator. The exciter to the regulator if you will.

 

[LiveFreeOrDieTryn2B]

Yes that wire is your relay without going out to look you should only have 3 wires +,-and relay but don't quote me on that.

 

[Mayapple]

That's what it looked like on the schematics. Just wanted some confirmation.

 

[LiveFreeOrDieTryn2B]

If I'm not mistaken if you don't hook up that small wire it won't charge if your new alternator doesn't have the male pig tale make sure to swap it over.

 

[Mayapple]

With the external regulator I wired it to the ign side of the regulator, per the instructions. So, hopefully, it will excite the regulator and control the new alternator through the field wire.