Alternator/battery question

[handirifle]

My MF1010 has been acting up a bit lately. I have noticed for a bit that the alternator light seemed to be coming on more than usual (as in not at all before).

Then the last couple days it wouldn't turn over(on starting), or turned over very slowly, and then the usual clatter of the starter not getting enough juice. Using the jumper portion of the batt charger starts it right up.

I finally got the battery out of today, it's a real PITA to get to, and I noticed that about 3 cells were dry or nearly so. I filled them up with distilled water, and put the 10 amp charger on it for 1 1/2hrs. I then tested it with my specific gravity tester, the ones with the squeeze bulb and it gives you a reading from each cell, and I got zero readings from any of the cells. Well, I was heading into town anyway, and took it to the batt shop and he tested it under load on his machine. says batt checked out OK.

I asked about the alternator and he said to start the tractor, and when it's running pull the red lead off the battery, and if it dies, the alternator is bad. i did that, and it kept running. So I figured the alternator is OK, and since he said the battery is OK, I should be good to go.

I started using the tractor, and sure enough, the light comes back on, and stays on till about 2000 rpm. So I am thinking next, the batt might not STILL be fully charged, so I just set it up with the 1.5 amp trickle charger, to maintain it overnight.

Does it sound like I am on the right track here? The belt for the alternator is still as tight as it's ever been, so it's not slipping. If the light comes back on, what would you suspect? It's been years since I looked, but I MIGHT have an alternator tester (shunt type), but am not sure.

Suggestions?

Thanks

 

[devildog1]

Get your multi meter out and check voltage of battery after charge , should read about 12.75 to 12.90 volts. Now start your tractor and check battery once again, should read about 13.35 to 13.55 volts.
DevilDog

 

[BigBoyinMS]

I know just enough to sound like I know something, sometimes.
First, taking the cable off while it was running probably didn't harm anything but you can damage a diode doing that.
Second, an alternator has to have a little current to start charging and it also has to have a bit of resistance in the charge circuit, such as a volt meter, ammeter, or "no charge" light for it to start charging at a low RPM. I don't know about all alternators but a standard Delco internal regulator alternator hooked up as a 1-wire alternator will not start to charge till you hit around 1600-1800 rpm. But the "no charge" circuit is working on yours. Sorta sounds like a diode may be bad. I would be getting the alternator tested.
And I'm really surprised the battery tested good after being dry in half the cells.

 

[sjb]

If your charge light is only coming on sometimes, and goes out when you speed up the engine, the first thing that I would check is the alternator brushes.


Stan

 

[handirifle]

OK so it seems like most suspect the alternator. I will see what the voltages measure.

If it does the same thing as before, I will pull the alternator next and get it checked.

I will post updates. Thanks for the feedback.

 

[Soundguy]

yep.. check the voltage.. if it ranges from sub 12.7 to 14.7 then the alt may eed help. might be bad slip rings.. etc..

soundguy

 

[handirifle]

Well the static voltage was 13.07 and when running was 12.47, so I will pull the alternator and have it looked at.

 

[Soundguy]

yep.. got some issue there.

I'm surprised static was soo high.. 12.6 is about nominal on a la battery like that, unless it just came off a charge.

in any case.. see what happens with the alt..

soundguy

 

[sandman2234]

Dumb question, but is the belt tight?
David from jax

On edit,

Opps, posted that in the original description... duhhh

 

[BeeferMan]

If the tractor is a diesel with a manual shutoff, it'll most likely keep running even if you pull off the battery cable...

 

[Soundguy]

hmm.. that mf 1010 is an early to mid 80's to mid 90's tractor with a toyosha diesel.. about 16hp if I recall correctly. not sure what method of fuel stop it has.. pull cable or solenoid. it didn't sound like he talked to a dealer service tech who told him to th do the cable test ( not one i would do ).. sounded like someone at an auto/electric shop.. so.. to the OP.. does it have a fuel stop solenoid, or a pull to kill cable, or do you dump the throttle to kill it?

soundguy

 

[Qapla]

You said you checked the belt ... but, did you check the wire connections. You may have a lose connection on one of the wires.

That said, I suspect a bad alternator.

 

[BeeferMan]

No idea how the MF1010 fuel shutoff works, I was speaking in general...

I'd not necessarily trust the auto store battery testers, I had problems with my Case - wouldn't seem to hold a charge. I checked the alternator (using a multimeter!) and that seemed ok, So I took out the battery and had it tested, they said it was fine. That just didn't seem right, so I temporarily put a different (much smaller, as that was all I had) battery in and no more issues. Bought a new battery and no problems since.

But having said that, if the alternator voltage measurements listed above are correct, I'd suspect the alternator...

 

[Soundguy]

I'd not necessarily trust the auto store battery testers, I had problems with my Case - wouldn't seem to hold a charge. I checked the alternator (using a multimeter!) and that seemed ok, So I took out the battery and had it tested, they said it was fine. That just didn't seem right, so I temporarily put a different (much smaller, as that was all I had) battery in and no more issues. Bought a new battery and no problems since.

I heard that. had a bettery dieing issue in my wifes yukon.. MM showed correct alt voltage .. battery was under warranty, and I took it in to the store I bought it from and they tested it. first test failed as battery was discharged ( did it overnight ).. they had to keep it, charge it al lday then retest.. tested ok. ( was a 3yr battery with a few months of warranty left.. ie.. near 3ys old. apparrently on their chart, it can test at 80% of it's rated output at that age and be ok ).. in any case.. it did it again the next weekend, 3 times in all, I had the battery back to the store. got good at taking it out they had me bring in her truck to test votlage of charge system. I used a spare tractor battery I had.. an interstate, in her truck during the 'week' that her battery was failing / being tested. I mentioned that her truck was running fine on the spare, and didn't kill it overnight like the other one. finally after 3 testings, and dieing 3 times, It kept testing right at the 80% it needed to pass.. I think the guy either fudged it to 79% to fail it.. or it actually hit 79% on the final test and they replaced it under warranty.. or at least.. gave me the pro-rated credit if I would buy another battery from them which i did. was simply cheaper than buying another somewhere else. In the end, i used their 'cheap' battery as my tractor battery and kept the interstate in her yukon.. both are doing fine..

soundguy

 

[jonyyuma]

Okay so Now you can see how well the cheap battery holds up to vibration and sitting in tractor?

 

[Soundguy]

it's actually the 'spare' tractor battery. IE.. not in use

 

[handirifle]

If the tractor is a diesel with a manual shutoff, it'll most likely keep running even if you pull off the battery cable...

Ha funny. I reopened this thread at page two, to find you guys talking about the fuel shutoff. I was thinkin "what the heck does that have to do with the battery?", so I went back to page one, and now I know:thumbsup:. Yes it IS manual, cable, fuel shut off, so I guess that test was a waste of time. not sure if I mentioned it was a tractor to the guy or not. The tractor is a 97 I believe, with a 16hp 3 cyl diesel.

This wasn't an auto parts store, it was just a battery shop, so I would HOPE he knew what he was doing when he tested it, and yes, the battery HAD just come off an overnight trickle charge.

So far it has started the last two days, but the light seems to still come on more than it ever used to, or at least that I notice anyway.

I did NOT check the connection, believe it or not but I sure will very soon.

Will be going into town today, so I will call around to find someone to test it, and hopefully have a replacement, if needed.

I will post. Keep the ideas comin though.

 

[Soundguy]

94 should have been the last year of manufacturer.. but then.. I'm not a MF expert either..

 

[Pete Judd]

Sounds like you have a diode going out. Hard to find, have to take the alt apart, and test each one. And as is intermittent may make it a lot harder.

 

[Baby Grand]

Back in the age of cars that needed constant maintenance I came to know the HTFCS (holy trinity of the failing charging system): battery, alternator, voltage regulator. Do tractors use a voltage regulator?