notjustair
Well-known Member
This has always puzzled me - the tractor has done it since I've had it. IH 886. It is charging the right amount - 14.5 volts or so. At idle the volt gauge slowly fluctuates - maybe 60 times a minute. It is varying from full charge to maybe a volt less. Not down to discharge or anything. If you throttle it up a little it fluctuates faster. When you hit a magical spot (1500 rpm or so) it charges steady. It's not the gauge. The lights visibly show it happening at night. The original owner replaced the alternator in '97 and I assume he reused the pulleys. They seem a bit large to me. I think they are larger than the 4440 with the same alternator.
I've got older machines that idle too low for the alternator to charge. On those it either is or it isn't. None of the others have a voltage swing that matches rpm around idle speed. It's just always kind of annoyed me. At night when you are feeding and idle it down you feel like you are in the twilight zone. The work lights fluctuate in brightness but not enough to be very noticeable. Just enough to make you wonder whether they are or whether you are at some bad nightclub that smells like manure and diesel fumes.
I've got older machines that idle too low for the alternator to charge. On those it either is or it isn't. None of the others have a voltage swing that matches rpm around idle speed. It's just always kind of annoyed me. At night when you are feeding and idle it down you feel like you are in the twilight zone. The work lights fluctuate in brightness but not enough to be very noticeable. Just enough to make you wonder whether they are or whether you are at some bad nightclub that smells like manure and diesel fumes.