Generator Confusion

[Erik B]

Seems every time I read a new thread about generators, I get more confused than I was before. Maybe someone could shed light on a couple questions:

1. Does a (stock) '48 B have a three-brush generator? I've read about generators with regulators, 3rd brush without, etc., and don't know what I have. It has what looks like a regulator mounted on top, three terminals on one side plus a vertical resistor, and one terminal hiding on the back, toward the rear.

2. When I plow with the B in the winter, it's pretty much always dark out. The generator can't seem to keep the battery fully charged in the winter, and I'm out for 45 minutes to an hour with lights (standard JD two facing front, one in the back lights) on the whole time. Is this normal, or is my generator weak?

 

[John T]

Erik, I cant answer alllllll your question and explain in a few sentences here what takes over an hour to do so in my Generator Seminars at GOG or Expo etc but will lay a bit on you.

QUESTIONS

1. Does a (stock) '48 B have a three-brush generator? I've read about generators with regulators, 3rd brush without, etc., and don't know what I have.

If it has that 4 terminal Voltge Regulator you described, its likely a 2 brush generator, but I dont have time to run your SN and Genny charts right now (Ive seen some 3 brush that still used a VR). If you look at your genny at the brush end its easy to count them. Basically the older tractors with a 3 brush genny didnt have a Voltage Regulator but instead had the 3 position (Low Charge, High Charge, Lights) light switch and 2 terminal cutout relay. Then the later tractors used a 2 brush genny and a VR versus the cutout relay.

QUESTION
It has what looks like a regulator mounted on top, three terminals on one side plus a vertical resistor, and one terminal hiding on the back, toward the rear.

Yep thats a VR and Load Bat and FLD are side by side while ARM/GEN is underneath or on one side all by itself

2. When I plow with the B in the winter, it's pretty much always dark out. The generator can't seem to keep the battery fully charged in the winter, and I'm out for 45 minutes to an hour with lights (standard JD two facing front, one in the back lights) on the whole time. Is this normal, or is my generator weak?

Your genny is weak or the belts loose or the battery is at fault. To see if non charging is a fault of teh genny versus a VR or other problem, run Par 5 of my test below

Sory so brief but I gotta run. Pat browning has some good info over on his web site that may help

John T

 

[Erik B]

Thanks John, now I know what I"m working with.

As far as charging issues, I think it"s the generator itself, as I redid the bracket and belt, and put a new battery in. I"ll check out your test procedure.

 

[Kurt_JDB]

John T

As a data point, my '51 B has the original generator, (confirmed by the tag and the generator listings in the JD book) and it is a three brush generator. It also has the four pole VR.

So Erik may also have a three brush generator to my way of thinking. Sure is easy to pop the band off and have a look. He might find he can move that brush and increase his output.

Kurt

 

[Erik B]

Thanks for that tip Kurt, I think I'll try that. When I had the generator out, right after I bought the B, to retap one of the mounting brackets, I couldn't find any easy way to look into the thing. That was before I had any manuals, so I didn't want to take out the screws on the back, thinking the whole interior might then come out. Can just the back be removed?

 

[M-MAN]

Your winter condition is normal for a genny. Winter condition only?

From your description your tractor is running with a max load all the time in winter & the genny doesn't have any extra juice to overcome the cold conditions much less what you used cranking it up.

Per John Deere Service Bulletin No. 199 - Cold weather charging. For winter use move the BATT wire to the L terminal on the regulator. This will increase output. Change the wire back to the BATT terminal in warm weather to prevent overcharging. Hope this help's.

 

[John T]

I hear you, thanks, I had a later model G with a 3 brush genny and still a full fledged Voltage Regulator myself, its generally true about 3 brush went with cutouts and 2 brush with VR's butttttttttttt Mother Deere sort of danced with the one that brung them lol. I always wondered why they started with 4 pole (what many consider superior) VR's but then went back to 3 pole also, Im sure cost had something to do with all this

John T

 

[k1r2]

John T, you seem to have a lot of experience with generators. I've posted a question in tractor talk with a pic.

Would you take a look and tell me what make you think make (i.e. delco-remy, etc.) this gen. is?

Thanks for your time,

http://forums.yesterdaystractors.com/viewtopic.php?t=1267297