Green Tractor Talk banner

1 - 20 of 27 Posts

·
Registered
Joined
·
28 Posts
Discussion Starter #1
Hey guys, just picked up a nice 40-W and the battery won't charge. Previous owner said he just rebuilt the generator thinking it was the issue, still won't charge, and then replaced voltage regulator with one from tractor supply and still didn't solve issue. Where should I look next? Or how should I diagnose this issue?
Thanks
Brian
 

·
Registered
Joined
·
321 Posts
Here is the wiring diagram for the 40. The wire coming off the center terminal of the regulator going thru the ammeter on to the neg post of the battery is the wire carrying the charging voltage. It's always possible that the previous owner put the wires ion a wrong terminal at the regulator. I hope you know how to read a diagram and use a meter for troubleshooting. Also it shows the 40 as using a POSITIVE GROUND, keep that in mind.

http://www.jd40.com/wirediags/wire12.pdf
 

·
Registered
Joined
·
28 Posts
Discussion Starter #3
Gimmo - thanks for the info. Not very good with the meter - yet - but I can read the wiring diagram. The previous owner had gen rebuilt, replaced voltage regulator, but it's still original ammeter. When I turn the switch to on/start, the ammeter does not does not move... Once I verify the routing on the volt reg I think my next step may be to change ammeter. Would a bad ammeter cause my issue?
Thanks
Brian
 

·
Registered
Joined
·
44 Posts
Jeeze its been awhile since I messed with a genny but don't they need to be polarized if components are changed/unhooked?
 

·
Registered
Joined
·
321 Posts
Gimmo - thanks for the info. Not very good with the meter - yet - but I can read the wiring diagram. The previous owner had gen rebuilt, replaced voltage regulator, but it's still original ammeter. When I turn the switch to on/start, the ammeter does not does not move... Once I verify the routing on the volt reg I think my next step may be to change ammeter. Would a bad ammeter cause my issue?
Thanks
Brian
If you can read the diagram you can do the rest. Yes ammeter has to be good for the charging circuit to be complete. If the ammeter is bad then you have an open circuit (same as a broken wire). If you suspect the ammeter as being bad then check the voltage to the ammeter terminal that has 2 wires on it (one meter lead on this terminal & the other meter lead to battery negative post), then put the meter lead on the other ammeter terminal. If the ammeter is good then you will get the same readings on the meter. You can also just put a jumper wire across the 2 ammeter terminals, the only thing then is the ammeter will not work, but the charging circuit would be complete so charging would work if everything else is good. Let us know what you find. Good luck
 

·
Registered
Joined
·
28 Posts
Discussion Starter #6
Ok, I checked the wiring and everything seems to be wired correctly. Jumped mostly everything I could and still no change. The ammeter won't move still, even jumped in a second ammeter I had and it didn't move... What about polarizing the generator? Or should I just switch over to 12 volt??
 

·
Registered
Joined
·
321 Posts
Ok, I checked the wiring and everything seems to be wired correctly. Jumped mostly everything I could and still no change. The ammeter won't move still, even jumped in a second ammeter I had and it didn't move... What about polarizing the generator? Or should I just switch over to 12 volt??

A 12 V circuit would be better to have in the long run BUT it is not as easy as just changing out the battery and then you no longer have an JD-40 in its originality. It would probably be more expensive also. It would be up to you in which manor you would prefer.


I found some advise on other tractor sites that explains the polarizing of a positive ground tractor and the troubleshooting of the generator and regulator better than I could (and I don't have to rack my brain and type it all out).

explains polarizing-------- http://fergusontractors.org/fena/wp-content/uploads/Polarizing-a-Generator.pdf

explains troubleshooting generator and regulator------ polarize positive ground - Yesterday's Tractors

I'm sure there are others on here besides me that are interested in finding out how your troubleshooting turns out so please keep us informed.
 

·
Premium Member
Joined
·
9,686 Posts
I'm sure there are others on here besides me that are interested in finding out how your troubleshooting turns out so please keep us informed.
I'm one of those interested others......:thumbup1gif:
 

·
Registered
Joined
·
28 Posts
Discussion Starter #10
So I noticed something today while playing around with the 40. The battery is pretty much dead. I don't have a 6 volt charger. I've been jumping it off a 12 volt battery. So when the tractor is running and I switch the lights on, it's shuts the tractor down in a matter of seconds. Ammeter don't move but it does work. Any thoughts? Gunna try polarizing tomor
 

·
Registered
Joined
·
321 Posts
If you are taking the jumper cables off after you get the tractor running and it stays running with a dead battery then it must be generating some or it would die as soon as you take the jumpers off. You can't troubleshoot the charging system unless the battery is at full charge. Your problem may only be a bad battery. You can charge the battery with a 12V charger just don't leave it on very long and charge at the lowest amperage setting. Disconnect occasionally and check battery voltage and when it gets up over 6V stop charging. YES CHARGE BATTERY THEN POLARIZE BEFORE DOING ANYTHING ELSE.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #12
So I charged the battery today, it's an 8 volt, and installed it back in the tractor. Checked with the multimeter and was at roughly 8 1/2 volts. Was starting to rain so I didn't polarize the gen after putting battery back in. Started right up, no change on the ammeter. But when I turned on the lights, it continued running, and the ammeter was at -10. So with the lights on then switched to off it would go from -10 back to zero... So tomor I'll check the voltage and see if it dropped overnight. Which I believe would be a bad ground(?). I'll also polarize the gen and see what happens. Making progres on the issue I think. Thanks for the help so far!
 

·
Registered
Joined
·
321 Posts
The battery voltage will probably be slightly less only because you used some of its energy starting the tractor and running the lights without recharging it. A bad ground does not change the battery voltage. If you had a bad ground it probably wouldn't turn the engine over fast enough to start it. Now that you have the battery at full charge, polarize the generator. You now know that the ammeter is working so after making sure that the wiring is all connected properly according to the wiring diagram, do the testing steps. The generator first, then the regulator to see which one has problems.
 

·
Administrator
Joined
·
20,852 Posts
If I had a bad ground wouldn't it drain the battery?
No really. Bad grounds prevent power from being used. A malfunctioning switch or component can drain the battery, such as a bad voltage regulator.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #17
Yes, you are correct, I'm thinking of a short not a bad ground. So maybe it's a short. Interested to find out tomor what the situation is. Thank you
 

·
Registered
Joined
·
4 Posts
I've had the same problem before. Rebuilt generator and new regulator and still no charge. I bought two voltage regulators and the second one worked for a day then quit. I even bought a $100 one from Deere that lasted a week. Then I read in the Green Magazine that these Chinese regulators arnt coming out of the factory adjusted properly. I took mine to a generator shop and after they adjusted it it's been fine ever since.
 

·
Registered
Joined
·
5 Posts
I believe you said you verified the positive post does have the ground cable connected to it. When I got my 1957 JD 420W the battey was installed backwards and had the polarity reversed, in other words it had a negative ground like our cars and trucks do nowadays. I removed the starter and ground cables and physically turned the battery around then connected negative post to starter and positive post to the ground cable, started it up, gave it a little throttle and the amp meter showed a positive charge rate of about 5A. It charges good enough that I do not need a battery tender, as long as I start it at least once per month and drive it around for a few minutes. If I leave it sit for awhile I disconnect the ground cable just to make sure I open circuit the battery. Sorry if this is redundant.
 
1 - 20 of 27 Posts
Top