Anatomy of a Deuce Generator

[3rdmdqm]

Last year my generator crapped out and I replaced it with one of the Wolverine Technology single wire alternators from Avengeusa which has been working great ever since. Figured I would take the old one apart and fool around with it to see what makes these things tick and maybe even repair it for a spare if I could identify the problem. Below are some pics of the generator (I'm guessing it's a generator since it says generator on the ID plate in pic1). I removed the side cover plate to clean up all of the connections where the wires enter the housing in case there was an issue and removed all of the caulk like material exposing all of the wires. I then removed the rear cover back plate exposing the interior electronics and brushes etc inside. Brushes appeared to be in good shape and I cleaned up all of the interior contacts etc (Pic2). Pic3 is a shot of the cover plate itself with a brass metallic cylinder. Notice one of the ends looks like it popped out. It was like this when I first removed the cover and I'm thinking this is the problem. There is a very thin wire coiled inside, when this popped out it looks like the coiled wire broke. Pic4 is a shot of the wire after I removed the cylinder from the plate. Anyone know what this is or what it does?

 

[steelandcanvas]

Looks like a resistor. 50 watt rating, but can't see how many Ohms of resistance. Google the number and see if you can get another one.

 

[3rdmdqm]

Google is a wonderful tool. Says it's a 50W resistor. Cost, about $10.00. Now that would be pretty good if I fixed this gem of a generator for $10.00

 

[steelandcanvas]

I had a few minutes so I Googled it for you:
QUESTION NO. P719-4: I need a source or sub for Vishay-dale wire wound resistor , part # RH-50-135 (50w 1.5Ohm 3%). Mouser Electronics (www.mouser.com; 800-346-6873) lists the Vishay "RH" series of resistors. Their catalog# 71-RH50-1.5 will replace RH-50-153 (the corrected part#). Mouser also carries the Xicon brand; their catalog# 284-HS50-1.5F might substitute.
Here's the link where I found the info:
Archive Component Cross Reference Answered Questions

 

[Warthog]

Check out the Alternator/Generator technical manuals. They don't show the resistor but may give you some guidaince. Both are available in the Resources Section

TM 9-2920-225-34 and TM9-2920-225-34p

 

[swbradley1]

I would wonder why that resistor burned out in the first place.

sw

 

[3rdmdqm]

Not sure what caused it to burn out. Looked like the end or interior degraded and the end cap worked its way off stretching the wire, however what would cause that I don't know unless it was faulty craftsmanship on initial install and they just soldred it poorly pulling on the end causing it to dislodge. Inside it was all chalky and crumbly.

 

[stumps]

This type of resistor is a coiled nichrome wire element, and the heat is drawn away from the element by a ground up ceramic substance.... the chalky substance you saw inside.

They are very sturdy, but if any moisture wicks its way through the seals, they will blow the end off of the aluminum housing.

I would just replace it and I think you will find everything is ok.

-Chuck

 

[3rdmdqm]

Thanks everyone for the replies, especially SteelandCanvas for the research and part info. I just ordered the part from Mauser Electronics ($4.69). If replacing this part makes this a working generator I will be very happy.

 

[glcaines]

I would definitely order a new resistor and repair it. This should be a simple fix and you will have your generator back.

 

[steelandcanvas]

Thanks everyone for the replies, especially SteelandCanvas for the research and part info. I just ordered the part from Mauser Electronics ($4.69). If replacing this part makes this a working generator I will be very happy.

As always, my pleasure. Get back to us and let us know how that new part works out for you, and if it does the trick. Good thread, I like the ones where we learn something.

 

[Alredneck]

Man this is a pretty good thread. I have been looking for a place to rebuild these for a few years now. No luck so far. I dont even know anyone that sells a rebuild kit. But if components can be bought indivdually for a reasonable sum then its possible to fix these ourselves or put together a kit for others to do the same! Good info, let us know how it works.

Also is there a way to test the 24V alts and gens? I have a 24V alt on my Allis Chalmer 645M Wheel loader that is not puting out a charge but cant find nooen that can load test it for me! Any ideas.

 

[cranetruck]

I would wonder why that resistor burned out in the first place.

sw

My first consideration also. The resistor was overloaded IMHO, depending on where it is in the circuit, but could be from a "load dump" caused by a poor battery connection. There may be colateral damage...

 

[FMJ]

 

[doghead]

BTW, it's an Alternator.

 

[jonesal]

This exact same thing happened to me this fall. You can check the main generator to see if it's still good by grounding the brush on the left side and it will run wide open. I only suggest doing this momentarily and on a good bench tester. The unit will definitely draw way more than 60 amps with rating limited by the regulator. I replaced the resistor (in the regulator) and it now works just fine. I agree that the unit was likely overloaded leading to the resistor failure. I carry a spare regulator in my tool box as they can easily be changed on the vehicle and of the several I have overhauled, the regulator was most always the culprit.

Parts for these are readily available on eBay, just keep an eye out for the repair kits. The regulators are always listed by a company in MI. The hardest thing to find are the Teflon seals and making the tool to install the front seal. Prestolite and other companies still make parts for it but you pay through the nose. The Prestolite manual has the civy to military part number exchange (which seems silly as this unit was never offered civy - suppose an internal parts tracking thing).

Allen

 

[3rdmdqm]

I thought alternator too, since it has brushes. But says generator on the ID plate which threw me off. Generator..... alternator......... generator......... alternator.........so many choices, lol. The regulator spoken of, is that where the exciter wire goes to? And is it mounted on the firewall somewhere?

 

[stumps]

I thought alternator too, since it has brushes. But says generator on the ID plate which threw me off. Generator..... alternator......... generator......... alternator.........so many choices, lol. The regulator spoken of, is that where the exciter wire goes to? And is it mounted on the firewall somewhere?

Virtually all automotive "generators" built after about 1963 are really alternators. All automotive alternators traditionally have had field brushes.

The distinguishing difference between a generator and an alternator is a generator natively puts out DC, and an alternator natively puts out AC. In a car/truck application, there are silicon diode rectifiers used with alternators to convert the AC to DC. Because of the DC output, they are sometimes called generators.

The reason that alternators came to be preferred over generators is they are capable of being spun at much greater speeds than DC generators. This allows you to get full charge current and voltage at idle. DC generators would throw out their field windings when operated at cruise speeds, if you picked a pulley that would spin them fast enough to get full charge at idle speeds.

-Chuck