Alternator not working on new Deuce

[midcounty]

Brought my Duece home last week, and noticed then the volt gauge was staying in the yellow. I just got around to checking it out, and sure enough my alternator is not working. I have rebuilt a number of alternators in the past for 12v automobiles, but have never messed with a 24v. Anyone know where I can get parts to do a rebuild on the Duece alternator? I'm sure the rebuild isn't much different then any other alternator, and something I can do myself. I am guessing after testing with my meter that I have a bad brush or voltage regulator. I figure a new regulator, set of brushes, and the diodes are all I should need.

 

[ctmustang]

Don't start the rebuild yet. Many of us have gotten our newly acquired deuces home to find out that they are not charging. After you clean all the connections at batts. and alternator and grounds try this. On the generator or alt. there is a plug on the top that takes an allen wrench to remove. After you get the plug out try turning the adjustment screw which adjust the voltage. Make sure you have someone watch the volt meter while you're turning make sure the engine is running but be careful. This has brought back every no charging alt on my deuces to life and are still all going strong. I hope this helps you.
CT

 

[midcounty]

Ah! I was wondering how that worked. I turned the allen screw, but didn't realize it was just a plug and the adjustment was under it. Thanks a bunch! I will try it out in the next day or so.

 

[rlwm211]

Be sure to insulate the sides of the small screwdriver to prevent shorts. The screw you will be adjusting is "LIVE" is you inderstand my meaning.

RL

 

[midcounty]

No go I removed the plug, but there was nothing under it to adjust. There was a small spring clip looking thing just laying in there. I'm wondering if someone tried it before and backed it all the way out, if that is possible? Sounds like it definitely will have to come apart or be replaced

 

[midcounty]

Been doing some reading, and seems regulators are the main failure. So went ahead and ordered a regulator and will try that first.

 

[TheDoubleDeuce]

I don't mean to steal the post; I just have a couple basic questions related to this:

Was I wrong in thinking my deuce had a generator, not an alternator?

What's good charging voltage on a 24v system?

If I install a battery quick-disconnect on one of the batteries, is there the potential for harm if I forget to re-connect the battery?

 

[SCSG-G4]

Early deuces had generators, most were replaced with alternators.

26.8 to 28 volts for the charging .

If the battery disconnect is working properly, it will be tough to start without a slave cable or a pull/push.

 

[rlwm211]

Typically a 12 volt battery wants to top out at right around 13.8 volts give or take a tiny bit. 13.8 is what is called the float charge point where you can keep that voltage going to the battery and it will not overcharge and it will not boil out.
Multiply 13.8 x 2 and you get (wait a minute, gears slowly turning in head making smoke) 27.6 volts. When your batteries are down the voltage can be lower until they come up to charge and under high demand on the system the voltage can actually be a volt higher or even a bit more.
I am sure if you look in the unit maintanence manuals for the deuce there will be the procedure to set the voltage regulator and if that is how the military says it should be done, well darn it, that is how it should be done.....

RL

 

[midcounty]

Thanks guys for all the help! I got a regulator from Erik's for 60 bucks. I put it on today, and bingo charging like a champ. I haven't put a voltmeter on it yet, but it's right where it's supposed to be on the dash mounted gauge. Yay! No 400+ dollar alternator needed.

 

[doghead]

Be sure to insulate the sides of the small screwdriver to prevent shorts. The screw you will be adjusting is "LIVE" is you inderstand my meaning.

RL

I respectfully disagree, I have never seen one that was "live" as you state. It's a simple potentiometer, the screwdriver slot should NOT have any electrical connectivity to voltage.

 

[midcounty]

I respectfully disagree, I have never seen one that was "live" as you state. It's a simple potentiometer, the screwdriver slot should NOT have any electrical connectivity to voltage.

I have to agree here. I looked over the new regulator before swapping it out, as I am just one of those people who just has to know exactly how something works There is no way for the adjustment screw to be energized, unless something were to go really wrong with it.

 

[JasonS]

I have to agree here. I looked over the new regulator before swapping it out, as I am just one of those people who just has to know exactly how something works There is no way for the adjustment screw to be energized, unless something were to go really wrong with it.

Ditto. It'd be a phenomenally bad design if the pot adjuster was energized.