Generator ID

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
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carl51
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Generator ID

Post by carl51 » Wed Nov 15, 2017 3:45 pm

Can anyone help me identify which model of 6 volt Generator I have? I purchased this at Tower Park a few years ago, I think from Paul Fitzgerald. Paul, I know this is a stretch but maybe you can help remember the model of this rebuilt generator. I would like to polarize the generator but can not be certain which model this is or whether it is an A or B circuit. It has a blank data tag and no markings on the housing that I can discern. My GPW has been completely restored and runs well, except that the ammeter needle does not go above 10 amp+ at idle or at higher rpms. The new Optima battery is steadily draining, so I thought the failure to polarize the generator may be the problem. I am assuming that I have a B circuit generator, however, I do not want to use a B circuit polarization method if I have an A circuit generator. Can these photos help with the ID? Many thanks for your help.

Image

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Carl
MVPA #36317
MVCC #1762
GPW #117302 DOD 5/21/43 Louisville, KY
MB #210593 DOD 2/11/43 matching frame & body under restoration


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Michael O.
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Re: Generator ID

Post by Michael O. » Wed Nov 15, 2017 4:40 pm

Looks to be a GEG-5002 series. If your pulley is marked SP-484 (A) then you have a GEG-5002D set up...which is correct for the g503. Many other vehicles used the 5002 series, but the pulley determined the letter suffix....ie, “D”. This generator is of the Type B Type.

Looking at the terminal markings, your housing appears to be a correct Autolite housing which are indeed different from the Ford produced version of the GEG-5002D.

The tag looks to be a replacement as the original tag was stamped with the model number, a date coded serial number and the amperage rating.
Michael O’Connell

Too many jeeps…and a Dodge.

MVPA 13861

carl51
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Re: Generator ID

Post by carl51 » Wed Nov 15, 2017 10:40 pm

Thanks, Michael. I looked at the generator pulley and it appears to have a GTB - GPW marking.
Carl
MVPA #36317
MVCC #1762
GPW #117302 DOD 5/21/43 Louisville, KY
MB #210593 DOD 2/11/43 matching frame & body under restoration

Mike Wright
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Re: Generator ID

Post by Mike Wright » Wed Nov 15, 2017 11:15 pm

Carl,
You have a correct genny for a G503. Search generator polarization here on the Tech forum and you'll be fine.
HTH
Mike Wright
SEEKING MOTOR # GPW 2636
MVPA# 4341
GPW 2636, DOD 28 FEB 42, Reg# 2055811 (est)
GPW 104331 DOD 31 MAR 43, Reg# 20369321 (est)
MB-101008 DOD 27 NOV 41, Reg# W-2032462 (Original)
MB 438075, DOD 1 MAY 45, Reg# 20704591 (Original)
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Wolfman
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Re: Generator ID

Post by Wolfman » Thu Nov 16, 2017 5:05 am

One sure fire way to determine "A" or "B" circuit is remove the brush band to see where the field wire, from the filed winding, connects inside.
If the field wire is connected to the armature brush, you have a type A generator.
If the field wire connects to the ground brush, you have a type B generator.
Your generator looks rebuilt with new tags. Any tag could have been installed for cosmetic purposes.
The above check will tell the tale.
Mike Wolford
CJ-2A
VEP GPW
Comm./Inst. SEL
AOPA ( 50 yrs)
EAA ( 49 yrs)
4th Inf. Div. - 5th Inf. Div. - 2nd Armor Div. - CIB

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Michael O.
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Re: Generator ID

Post by Michael O. » Thu Nov 16, 2017 5:20 am

carl51 wrote:
Wed Nov 15, 2017 10:40 pm
Thanks, Michael. I looked at the generator pulley and it appears to have a GTB - GPW marking.
Then you have a Ford pulley installed on your Autolite generator...a bit of a salad but functionally you’ll have no problems. What are your end plates marked?
Michael O’Connell

Too many jeeps…and a Dodge.

MVPA 13861

Jerry Hudgens
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Re: Generator ID

Post by Jerry Hudgens » Thu Nov 16, 2017 2:14 pm

Polarizing the generator will not increase the output assuming the generator is putting out any current. Once the generator starts producing any output, the polarization of the field pole pieces is regenerative and self "polarizing".

Jerry Hudgens

carl51
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Re: Generator ID

Post by carl51 » Thu Nov 16, 2017 5:49 pm

Michael, I could not make out the marking on the end plate of the generator. Too much rust, wear and/or paint. I did polarize the generator using the B circuit method. A small spark at the BAT lead on the Regulator resulted with no mechanical noise of any switch or points movement. No change in the ammeter, still basically at or around 0+. I removed the Battery Negative lead while the motor was running and it continued to run, so I assume that the generator is OK. With the motor running, I have 7.4 - 7.6 volts across my battery terminals. I had another Voltage Regulator VRY 4230A and replaced the one in place. No change. I will now check the ammeter wiring. Probably should have done this in the first place.

Is there a test to see if the voltage regulator is working properly as my ammeter gauge may be suspect?
Carl
MVPA #36317
MVCC #1762
GPW #117302 DOD 5/21/43 Louisville, KY
MB #210593 DOD 2/11/43 matching frame & body under restoration

Wolfman
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Re: Generator ID

Post by Wolfman » Fri Nov 17, 2017 4:47 am

You just did it.
7.4 to 7.6 volts at the battery with the engine at fast idle is a beautiful thing.
I would be looking at the amp gauge.
Mike Wolford
CJ-2A
VEP GPW
Comm./Inst. SEL
AOPA ( 50 yrs)
EAA ( 49 yrs)
4th Inf. Div. - 5th Inf. Div. - 2nd Armor Div. - CIB


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