52 Cub decided to stop charging

67air

New User
I used my cub a few times over the Winter, but just last week I saw the AMP guage go into the negative. A volt meter confirmed that. 1st I tried the Gen to Amp 2 second zap to see if I could get it working-----It worked for about 1 minute in the positive then took a nose dive back to the negative. I got a new Voltage regulator yesterday & still no soap.

This was a similar scenario some 18 years ago when I bought her.I ended up having the generator rebuilt. I use her ever week with my Woods 59 deck to cut my lawn so I need the old girl !

THOUGHTS---? best way to test the generator without having to remove the upper cover?? I can't complain after 18 good years if the Gen needs a rebuild , but maybe I'm missing something simple here.Battery is OK BTW & holding a good 6.5 charge when not running.

Thanks for the help Members----
 
If you work through my Troubleshooting Procedure it can help determine the cause of non charging and if its a Generator or VR or other
problem, yours may well be the Generator is failing maybe due to worn too low brushes, a commutator or a fields or bushing problem or
whatever........ If when she's running if you ground out the Gennys FLD she charges (says the genny itself is okay) then but NOT otherwise,
the VR is bad or not well grounded (or a Low High light switch type problem if it uses a cutout relay). If no charge even with FLD grounded
and cutout relay by passed you have essentially by passed any VR or manual charge control system function, so if still no charge, sounds
like the genny is bad. I'm talking about a VR system here but even if its a Low High Manual light switch charge control my procedure still
applies..........

My procedure also includes the MOTOR TEST to test the genny

Try this https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=ttalk&th=2060825

John T
John Ts Charging Troubleshooting
 

Hi John , thanks so much. Ok so where do I find the Gen wire off the Generator. Can I just ground the Gen wire going to my VR & see what happens & then jump the batt & gen as per your note ?

I will also check my battery again. She's old (5yrs) but no corrosion & been cranking over quite well.
 
The Field wire can be grounded to assess the gen output. Don't ground the A terminal, or Gen terminal on the regulator, they are hot when running, and
not hot when stopped, but no information can be gained from that action. Jim
 

Dear John & Jim,
Ok, I just finished grounding out my field terminal attached to my VR when running & it didn't even blink-----I then gave the Gen to Batt one last try at a zap and nothing.

Sounds like a rebuild for the Generator is in order---Doing my math, the last Genny rebuild got me 18 yrs & 5670 Hours of use.

No complaints here !

I'll get back with you guys once I get the generator rebuilt.

Regards, Fred
 
when you ground the field and it doesent charge the gen is bad so you need to remove the hood and get another gen
 
The generators output is off the post labeled ARM. Its typically the larger of the two genny terminals FLD often being a bit smaller and ARM
often bigger. Its also the one that's wired to the terminal labeled GEN or ARM on a typical Voltage Regulator while the gennys FLD post is
the one wired to the FLD terminal on a VR

NO do not ground out the gennys output which is ARM on the genny or GEN or ARM on the VR. To do the full field test I described below you
ground the gennys FLD post which is wired to the VR's FLD terminal

Got it ???

John T
 
If grounding the gennys FLD post (wired to FLD on VR) doesn't make her charge and all else is in place and wired correctly and good
grounds ??? it appears the genny itself is the problem and NOT the VR. In addition another way to test the genny itself is my Motor Test
described in my procedure.

The genny may have a problem with worn brushes,,,,,,,,,brush hold down spring assembly bad or stuck,,,,,,,,,,,commutator is bad or
carboned or corroded,,,,,,,,,,,,fields are open or shorted to case/frame,,,,,,,,,,,bushings are bad,,,,,,,,armature is shorted etc etc..

Polarize the new genny before start up

Thanks for the feedback

John T
 
Grounding the field is only half of the needed testing.

If grounding the field does not make it show charge, leave field grounded and jumper from generator ARM or GEN terminal to BAT if this makes it charge you have a bad cutout, if it still does not charge then suspect problems with generator or wiring.
 
(quoted from post at 09:20:59 05/12/20) Grounding the field is only half of the needed testing.

If grounding the field does not make it show charge, leave field grounded and jumper from generator ARM or GEN terminal to BAT if this makes it charge you have a bad cutout, if it still does not charge then suspect problems with generator or wiring.

Thanks to all of you members. I'll keep you in the loop. The hood comes off this evening after work----

Fred
 

And YES John, last night I did ground out the "Field" post off of my VR & she did absolutely nothing. I'm 99% sure the Gen decided to take a 1 week vacation while I have her rebuilt. She doesn't owe me a dime !
 

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