alternator not charging battery!

plowman12

New member

Equipment
L245DT,FEL 1200,Woods rotary mower
Aug 9, 2014
28
4
3
colville,wa
The owner (me) of a L245DT did something stupid yesterday (left key in on position for about 15 hours) and now the alternator won't charge! I was able to jump start the tractor, but no juice is flowing to battery - all else seems fine.

Any suggestions on troubleshooting the alternator / wiring, or do you guys think the alternator is just toast?

Thanks in advance!

Chuck
 

85Hokie

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BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
Jul 13, 2013
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Bedford - VA
The owner (me) of a L245DT did something stupid yesterday (left key in on position for about 15 hours) and now the alternator won't charge! I was able to jump start the tractor, but no juice is flowing to battery - all else seems fine.

Any suggestions on troubleshooting the alternator / wiring, or do you guys think the alternator is just toast?

Thanks in advance!

Chuck
Have you checked all fuses? trace the wire back to the alternator post and see if you can get 12.6 + volts at the post!
 

olthumpa

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L275
May 25, 2011
1,501
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38
Maine
An alternator can not charge a battery that has been completely drained. If you have a battery charger, charge the battery cith the battery charger. If you can, have the batterry load tested. This will tell you the amount of amps that it can deliner and if it has been damaged by the complete discharge. Put the battery back in the tractor and see if it will start. If you have a proven good battery then you have an other problem. bad alternator - poor ground/commections - blown fuse - bad cables - other ellectrical problems.

Start with the easy and progress to the more difficult to eliminate.

That is what I would do.

Good luck.:)
 

plowman12

New member

Equipment
L245DT,FEL 1200,Woods rotary mower
Aug 9, 2014
28
4
3
colville,wa
85 hokie and olthumpa,
Great work guys, you saved me a lot of work trying to figure out a difficult problem with the simple solution! Blown fuse!! I had already put my charger to work once i saw the alternator wasn't charging. The battery is only 3 months old and had only been driven down to 12.2 V . Not totally drained but would barely crank the engine.

My alternator just puts out 13.5 V. Is that normal? Seems all my other vehicles put out 14 plus volts.

Again, thanks for your help!
 

ShaunRH

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L3200
May 14, 2014
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Atascadero, CA
To add on to olthumpa's comments.

It's not that the alternator can't charge the battery that is drained, a drained battery cannot energize the alternators coils so it can develop a charge (vicious cycle there!).

If you have a completely dead battery and jump it from a car, truck, other battery, etc., just leave the jumper cables hooked up for 15 minutes with the jumping vehicle running and it will bring enough life back into the drained battery to let it energize the alternator on it's own.

If the drained battery starts getting hot to the touch and does not hold up the alternator (accept a charge) it's dead shorted and needs to be replaced.

Not sure if that's clear as mud or not...
 

Tooljunkie

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L1501,home built carry all, mini plow blade.
May 13, 2014
4,150
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48
59
Lac Du Bonnet, Manitoba,Canada
Boosting a battery isnt all that good for it, but gets things going. Always best to fully recharge battery, never more than 15 amps. This insures a proper charge and lessens damage to battery from overheating.
Winter's coming so i will add....
A frozen battery needs to be thoroughly thawed before recharging.24 hours in a warm place is barely enough.
 
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