[Farmall] IH240U Charging Problem

[Mike Sloane]

The charging current for the battery goes *through* the ammeter. If the 
ammeter is dead and isn't passing current, then your battery won't ever 
charge from the generator. That might be one of the first places to 
look. If worst comes to worst, move one of the cable ends at the ammeter 
over on top of the other, essentially bypassing the ammeter. You can buy 
inexpensive ammeters at auto part places - they don't look nice, but 
they will at least tell you whether the battery is being charged (be 
sure to observe the correct polarity!).

Mike

Jim Jacoby wrote:
> Thanks for the tips Mike.
> 
> The belt is well tensioned, not too terribly old, and didn't seem to be wet
> when the tractor died.
> 
> The ammeter is inoperable, one of those things on the to-do list that has
> now moved up in priority.
> 
> I changed the battery because it wouldn't hold a charge, even when charged
> with a charger. It would only allow 2 or 3 cranks, so if the tractor didn't
> start in the first couple of tries, I had to drag the charger out to it
> again. The new battery fixed this particular problem.
> 
> I'd be interested in more details of your 12V conversion. Its something that
> I really wanted to do before I got the new battery, but that fixed the
> starting problems at least.
> 
> Thanks,
> Jim
> 
> On Dec 12, 2007 5:29 AM, Mike Sloane <mikesloane at verizon.net> wrote:
> 
>> There are a lot of things that could be causing your problem. The
>> easiest is a generator belt that is a little loose and slipping under
>> load, especially in damp weather. Another is a "dirty" commutator on the
>> generator or worn brushes or "soft" brush springs. Those are not
>> difficult to remedy, but some knowledge and/or experience would be
>> necessary. The generator almost certainly not a three brush model, nor
>> does it have the "high charge" switch that was on some of the 1940s era
>> IH tractors.
>>
>> More difficult to deal with is a voltage regulator that has gotten tired
>> - generally speaking, replacement is the best cure.
>>
>> Now, it should be noted that those old Delco tractor generators aren't
>> all that powerful, and if you are running at only a little over low idle
>> speed with all the lights on, it is certainly possible that the
>> generator couldn't keep up with the load. Have you been watching the
>> ammeter while you were working? If the needle isn't positioned on the
>> "charge" side of center, then the generator just isn't keeping up. If
>> you bring the engine speed up, then the ammeter should show a charge.
>> The type of use you are giving the tractor is exactly the reason I have
>> converted some of my old Farmalls to 12 alternator - snow plowing at
>> night for hours on end. See:
>> <http://public.fotki.com/mikesloane/international_240u/240u4140506.html>
>> for the conversion on my 240.
>>
>> And, finally, why did you change out the battery? If it was because it
>> wouldn't start the tractor, the problem might have existed back then.
>>
>> If you aren't experienced with taking generators apart and assembling
>> them, I suggest you remove it and take it to a local auto electric shop
>> for diagnosis - they don't usually charge a lot to clean the commutator,
>> undercut the segments, and install new brushes/springs (if needed). Some
>> of the older places will even let you watch! And, if you remove the
>> voltage regulator (carefully noting how the wires are connected), they
>> will test the entire system under load to see where the problem lies.
>>
>> Mike
>>
>>
> 
>