Alternator not charging battery. Alternator, battery, and fuses all check out fine.

   / Alternator not charging battery. Alternator, battery, and fuses all check out fine. #1  

MomNottaMechanic

New member
Joined
Mar 19, 2013
Messages
9
Location
Vienna
Tractor
TYM T450
If you're reading this, just know I am not a mechanic by habit. Husband is out of town for a while or I'd not be messing with this. So please forgive my ignorance should it show too much.

We have a TYM T450.

I am having to jump the battery on the tractor each time to get it to start. I assumed it was either the battery or the alternator that was the problem. I had both checked out by reliable mechanics that I could take them in to. Both checked out fine. I have downloaded the service manual and it shows the typical causes to be a belt that is not tight enough, bad battery or bad alternator. None of these hold true in this situation as best I can tell. I scrubbed down the posts with a cleaning tool my husband has and made sure everything was connected well. No problems there. I located each of the fuses and checked them with husband's meter thing. They all came out at .04 - .03. That seems to indicate they are fine. I've looked for any obvious wiring that might be loose, disconnected, or worn through. I can find nothing to indicate such.

The reason I really thought it would be the alternator is that when it is running, I disconnected the positive battery post connector and it instantly died. Also, when letting it run after having charged the battery, it looses charge slowly as the tractor is running (I watched it running down on the meter). However, the mechanic tested the alternator today and said it is just fine and recharges a battery there without issues. I had another mechanic check the battery and he said it was good to go.

Does anyone have further suggestions as to what I can look at? I cannot get this tractor on the trailer without help and we live an hour and a half from the nearest reliable mechanic that can work on it. Between reading the forums and googling, the above is all I can figure out to look into.

Any thoughts, guidance, or suggestions would be greatly appreciated.
 
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine. #2  
Run tractor at 2000 RPM or so, and measure the charging voltage on top of the battery terminals with your portable volt/ohm meter... Make sure the meter is on the volts DC setting on the 0 to 20 volts range or similiar range.. It should be somewhere around 14 volts. Then shut the tractor off, and measure the DC voltage on the battery, it should be about 12.6 volts. Turn on the lights with the engine off and watch the voltage for a bit.. Might go down to 12 or so, in 5 minutes. but should not dip below 11.5 in a short time.. if it does, I suggest you have a bad battery. If the charge voltage is not near 14 or slightly above, there is some kind of problem with the alternator. Or connections problem with the wireing. For instance ground cable. You can measure with your ohm meter the ground and positive cables and their connections after disconnecting the battery. They should be near 0 ohms of course. I am assuming the alternator has a built in voltage regulator as it is a modern tractor so I am considering the alternator and voltage regulator as a complete unit.. But you will never know if it is the alternator, or battery or connections without testing the system first as a complete system. Again if the charge voltage is where it should be, you can rule out the alternator/regulator. And I suspect you will find that the charge voltage is correct. I suspect defective battery.. I cannot account for the "good battery" test.. but you need to test the whole system while in operation to find out. Good Luck and get back with us with your results.

James K0UA
 
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine. #3  
If you're reading this, just know I am not a mechanic by habit. Husband is out of town for a while or I'd not be messing with this. So please forgive my ignorance should it show too much.

We have a TYM T450.

I am having to jump the battery on the tractor each time to get it to start. I assumed it was either the battery or the alternator that was the problem. I had both checked out by reliable mechanics that I could take them in to. Both checked out fine. I have downloaded the service manual and it shows the typical causes to be a belt that is not tight enough, bad battery or bad alternator. None of these hold true in this situation as best I can tell. I scrubbed down the posts with a cleaning tool my husband has and made sure everything was connected well. No problems there. I located each of the fuses and checked them with husband's meter thing. They all came out at .04 - .03. That seems to indicate they are fine. I've looked for any obvious wiring that might be loose, disconnected, or worn through. I can find nothing to indicate such.

The reason I really thought it would be the alternator is that when it is running, I disconnected the positive battery post connector and it instantly died. Also, when letting it run after having charged the battery, it looses charge slowly as the tractor is running (I watched it running down on the meter). However, the mechanic tested the alternator today and said it is just fine and recharges a battery there without issues. I had another mechanic check the battery and he said it was good to go.

Does anyone have further suggestions as to what I can look at? I cannot get this tractor on the trailer without help and we live an hour and a half from the nearest reliable mechanic that can work on it. Between reading the forums and googling, the above is all I can figure out to look into.

Any thoughts, guidance, or suggestions would be greatly appreciated.

Welcome to the forum.

You should never disconnect a battery cable on a running engine, it is a good way to fry anything electrical because you could have a voltage spike. With the tractor running at a fast idle take the meter and check the battery to see if the tractor is charging. Let us know how many volts you see. Charge the battery and let it set for a 2 hours then check it. 12.6 is 100% charge 12.4 is 75%, 12.2 is 50%, 12.0 is 25%, and 11.8 is 0%. Check those things out again and let us know what you find.
 
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine. #4  
As for alternator belt tension. of course it depends on the length of the span, but I usually leave about 3/8 to maybe 1/2 of and inch on a long span.. Most of our tractors are pretty short spans, so maybe 1/4 to 3/8..so relativly tight, but not TOO tight as to risk bearing failure. The only other thing I can think of if the charge voltage is not 14 or so, and the Alternator static test was good, perhaps a wireing or connection problem when the alternator is reinstalled. We are eagerly awaiting to see what you come up with.

James K0UA
 
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine.
  • Thread Starter
#5  
Thank you for the advice on not disconnecting the battery cable while the engine was running, Roger. That is how I saw Dad test to see if it was the alternator or battery so that is what I did. I won't be doing that one again!
Battery was at 12.6 when I charged it for 3.5 hrs yesterday. When I run the engine at a fast idle, with both the alternator and the battery connected, it starts out above 12 and slowly dwindles as the tractor runs. When it fell below 11.5, I shut off the tractor and knew the battery was not being recharged. That took around 3 minutes.
I'm finding references to a fusible link as a possible culprit. I really don't want to do any wiring but does that even sound like a possibility? Meaning the fusible link on the positive cable being a possibility as the culprit.
 
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine. #6  
Thank you for the advice on not disconnecting the battery cable while the engine was running, Roger. That is how I saw Dad test to see if it was the alternator or battery so that is what I did. I won't be doing that one again!
Battery was at 12.6 when I charged it for 3.5 hrs yesterday. When I run the engine at a fast idle, with both the alternator and the battery connected, it starts out above 12 and slowly dwindles as the tractor runs. When it fell below 11.5, I shut off the tractor and knew the battery was not being recharged. That took around 3 minutes.
I'm finding references to a fusible link as a possible culprit. I really don't want to do any wiring but does that even sound like a possibility? Meaning the fusible link on the positive cable being a possibility as the culprit.

Ok. you have confirmed that the alternator is not charging the battery for sure.. now as for the fusible link, you can use your ohm meter to measure between the positive cable (after removing it from the battery for safety (engine off) and the large red wire connection on the alternator stud.. If it is not a dead short you have a problem.. find the fuseable link or large fuse (like my tractor has a 60 amp fuse near the alternator) and repair/replace. Another way would be to measure the voltage on the alternator stud and it should be 14 volts or more, and you have already determined that the voltage on the battery positive terminal is not 14 volts. So they are not connected, and they should be..

James K0UA
 
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine. #7  
One other thing to check that often gets over looked is where the battery ground cable connects to the frame. This can cause a lot of problems and easy to fix. I have seen that cure the problem more than once.
 
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine. #8  
Thank you for the advice on not disconnecting the battery cable while the engine was running, Roger. That is how I saw Dad test to see if it was the alternator or battery so that is what I did. I won't be doing that one again!
Battery was at 12.6 when I charged it for 3.5 hrs yesterday. When I run the engine at a fast idle, with both the alternator and the battery connected, it starts out above 12 and slowly dwindles as the tractor runs. When it fell below 11.5, I shut off the tractor and knew the battery was not being recharged. That took around 3 minutes.
I'm finding references to a fusible link as a possible culprit. I really don't want to do any wiring but does that even sound like a possibility? Meaning the fusible link on the positive cable being a possibility as the culprit.

You won't have to do any wiring regarding the fuseable link. To clarify some manufacturers protect the starting circuit with a large amp fuse, (somewhere around 50-60 amps) to protect the starting circuit from overheating the wires under certain circumstances. Since your tractor is starting that is an unlikely suspect. If it were NOT cranking over when you turn the key to start the tractor, THEN it might be suspect.
Now from what you stated above, the charging system is NOT functioning correctly- and you ARE running purely off the battery's stored voltage, which is dropping even when you cause the idle to be high enough to have the alternator supply needed voltage back to the battery.
I'm not familiar with your tractor specifically, so here is what I suggest. Call the guy who tested the alternator and ask him if it has a built in voltage regulator, or if there is an external one, which would be separate from the alternator BUT located close to it on the tractor. I doubt it's separate but I could be wrong.
What needs to be done is to determine which part, battery or alternator, (or possibly separate voltage regulator), is NOT working currently.
I'm suspecting the alternator based on there being NO charge being sent back to the battery from the charging circuit. Also ask the mechanic that tested the alternator what exactly he did to determine the alternator is alright? You don't want to make it seem like you're questioning his diagnosis- just that you're still trying to figure out why the system is NOT charging your battery.
One thing you could try to help further narrow down the problem is take a known to be good battery and put it in the tractor and see what readings you get. BEWARE there are LOTS of battery post configurations which might NOT line up with the existing battery from the tractor. Sometimes one can get around this by carefully moving the cables on the tractor to reach the correct post, so check before trying to remove a battery from your car, for instance.
We'll help you solve this.
One caution: wear glasses around batteries, especially when charging them like the one currently in the tractor. Battery acid, even what gets on the outside of the case can burn your skin and clothing. When removing disconnect ground post first (negative), then positive and when reinstalling do the opposite. Household baking soda neutralizes battery acid so keep some within reach, just in case of any acid getting on your skin. When tightening the cable end to the battery post make sure it is not only clean but tight as well, and cannot be turned on the post by hand. Follow the ground cable from the negative battery post to where it attaches to the frame and make sure that connection is clean and tight too.
if you need to tend to the ground cable at the frame location first DISconnect it at the battery and remove the key from the ignition switch whenever doing any battery/alternator type work.
Post back results.
P.S. You're doing a good job and should be proud of yourself for tackling it on your own.:thumbsup:
BTW, what year is your tractor and how many hours on it? How old is the battery in years? Did this problem just crop up in the last few days or has it been going on for some time?
And, one last thing- all batteries have a date code stamped into the case usually on the side, which indicates when they were made, NOT when they were put into service- usually only the manufacturer has the 'key' to the code but you can call them and ask when it was made based on the code.
 
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine.
  • Thread Starter
#9  
Okay, question borne of ignorance....where is the alternator stud? On the alternator itself or is this something I should see on the tractor itself? I'm not seeing any red wires on the tractor that would be anywhere near where I connect the alternator up. There are no red wired on the alternator itself either.

I looked and am not seeing a fuse anywhere near the alternator. I followed the wiring diagrams and checked each fuse that connects to the battery or the alternator in any fashion. They all run between .03 and .04. No O.L.'s to be seen. The tractor starts fine as long as I jump start it or charge up the battery first.

I'll call the guy who tested the alternator. He was the only one I could find who could test it. I spent 2 days running to auto mechanics, Advanced Auto Parts, Napa, O'Reily's etc and none of them could find specs that matched up to test it. Several of them referred me to this gentleman since he tested "the old fashioned way" so I took it to him. I'll ask him how he tested it and if it has a built in voltage regulator or not, tomorrow morning.

I can get a loaner battery tomorrow from a friend. He sells tractor batteries so surely we can get a close enough match up.

Thank you for mentioning the precautions regarding battery acid. I would not have thought about it to be honest.

I'll check out the ground cable from the negative battery post in the morning. It would be so nice if it were that simple!

It is a 2006 and has about 250 hrs on it. We bought the battery back in October, new from a tractor dealer.

This has been going on for some time, but Husband is so busy with work he has not been able to address it. Please don't let me give you the wrong idea. He's not shirking his duties or the like. He is responsible for a lot at work and they are in the middle of an expansion right now. He got called away for a while. After standing in 11" of snow jumping the battery 2 wks ago, I got mad enough at it to decide to do something about it. Since I could not load it up to take it to a mechanic, I paid one to come out here and work on it. He arrived several days later and after an hour and a half, he told me he has no idea what the problem is and handed me a bill for $280. I refuse to waste anymore of my husband's money on jerks like that so ever since, I've been learning a lot more about tractors than I ever wanted to.

Thank you everyone for being so helpful and gracious. I so truly appreciate it!
 
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine.
  • Thread Starter
#10  
Okay, I'm starting to wonder about the voltage regulator. I have a headlight that is also a problem but just figured it was a light issue. However, I'm looking at the service manual that I downloaded and it acts like the voltage regulator is a separate piece from the alternator. It mentions lights not working right if your voltage regulator is faulty. Now to figure out what it is and where it is and how to replace it....fun fun!
 
 
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