# Charging issue



## Wrh859 (Aug 4, 2019)

1998 John Deere 770. Not charging. New battery, new alternator and new voltage regulator. Still not charging. Runs fine, battery light is on and testing volts at battery = 12.6 not running. And about 12.5 with tractor running. Any suggestions?? Thank you I am a new member here.


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## Hoodoo Valley (Nov 14, 2006)

Welcome to the forum Wrh! Only thing that comes to mind for me would be all the electrical connections tight and clean.


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## Wrh859 (Aug 4, 2019)

Hoodoo Valley said:


> Welcome to the forum Wrh! Only thing that comes to mind for me would be all the electrical connections tight and clean.





Hoodoo Valley said:


> Welcome to the forum Wrh! Only thing that comes to mind for me would be all the electrical connections tight and clean.





Hoodoo Valley said:


> Welcome to the forum Wrh! Only thing that comes to mind for me would be all the electrical connections tight and clean.


Thank you for your response. I will double check all the connections as well as clean the ground connections.


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## Wrh859 (Aug 4, 2019)

Still no luck. Any other ideas?


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## Wrh859 (Aug 4, 2019)

All connections look good. Cleaned ground wire behind voltage regulator and negative cable from battery to frame. Still not charging. What am I missing?


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## Hightech1953 (Dec 30, 2018)

Check the voltage at the alternator itself. Are you checking at idle if so rev the engine up and check. You could have a defective new alternator .


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## Wrh859 (Aug 4, 2019)

Could you tell me exactly how to check it at the alternator. Wiring has plug in connection. Do I unplug it start tractor and check the alternator side of the plug with it running?


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## Wrh859 (Aug 4, 2019)

Wrh859 said:


> Could you tell me exactly how to check it at the alternator. Wiring has plug in connection. Do I unplug it start tractor and check the alternator side of the plug with it running?


About the reving. I have checked it both reving and at idle at the battery, no change.


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## Hightech1953 (Dec 30, 2018)

Wrh859 said:


> Could you tell me exactly how to check it at the alternator. Wiring has plug in connection. Do I unplug it start tractor and check the alternator side of the plug with it running?


Yes , or you could pull it off and take it to a auto parts store and they will check it out for you.


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## gman51 (Mar 22, 2016)

From what I recently read an alternator should not be spun when it is unplugged. Take it off and have it checked.
Could be the new voltage regulator is bad also. You might ask the people where you bought it how to check it.
New or reman electrical parts are often defective right out of the box.

You might check and see if there is a fuse or breaker or fusable link that is bad. Trace all the wiring point A to point B with ohm meter for continuity or open wire.

Battery charging correctly should be 14 + at the battery. 12.6 you are just reading the battery voltage. 12.6 reading the battery is good.


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## dlbglocksmith (Jul 1, 2019)

New alternators that have been setting on the shelf sometimes loose their magnetism and they have to have excitation to get them started, after having been run and you don't leave them with out a battery connected for a long time you don't normally have the problem again.


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## FredM (Nov 18, 2015)

Check if there is a field wire coming from the regulator to alternator, turn ignition on and check voltage at field connection at alternator, you can remove this wire from alternator, this wont do any harm, if there is voltage to the field connection, then you have a problem with the alternator, there has to be voltage at the field connection to excite the alternator, once the alternator starts charging, it becomes self exciting and the charge light goes out, if there is no voltage at the field wire, then have the regulator checked for fault.


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## FredM (Nov 18, 2015)

FredM said:


> if there is no voltage at the field wire, then have the regulator checked for fault.


Belay that, been a long time since I worked on auto electrics, I implied that the field wire is part of the regulator circuit, it is not, but part of the ignition circuit, when you turn the key to run position, voltage is sent to the alternator through the charge light and then to the exciter/field connection, the fact the charge light is on when you turn the ignition on, shows the circuit is there, I would have the alternator checked, there could be a blown diode/s, seeing the alternator is new, it should be under warranty.


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## Wrh859 (Aug 4, 2019)

Thanks for all the info. I will have it checked.


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## Wrh859 (Aug 4, 2019)

Follow up. Got it Charging. Turned out to be a couple of things. The voltage regulator was bad but also there was a 4 wire plug about 1/2 way between alternator and regulator that was bad as well. Thanks for all the help everybody.


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