Tractor stopped charging

[cdahl383]

Brought my Cub to the Cubfest last weekend and got the brakes fixed with the help of several folks there. Got home and unloaded the tractor and put it back in the garage Sunday night. I flipped the switch from Low to High charge and the needle on the amp meter went kind of haywire and then it just dropped to 0. I turned the lights on and they all came on and it read a discharge on the meter, so I know the meter is still working.

Where would I start to diagnose the issue? Check grounds? Check switch itself? Do I have to repolarize the generator as I've read in a few other threads? I'm not too good with electrical stuff, but it doesn't seem like a very complicated setup on the Cub, so I'm hoping I can figure it out with a little help.

[SamsFarm]

There is a charging system trouble shooting guide here somewhere.

Might snoop around the site and find it, or someone will direct you to it shortly.

I recomend printing it out and keeping it in your Cub owners manual!

[Don McCombs]

Brought my Cub to the Cubfest last weekend and got the brakes fixed with the help of several folks there. Got home and unloaded the tractor and put it back in the garage Sunday night. I flipped the switch from Low to High charge and the needle on the amp meter went kind of haywire and then it just dropped to 0. I turned the lights on and they all came on and it read a discharge on the meter, so I know the meter is still working.

Where would I start to diagnose the issue? Check grounds? Check switch itself? Do I have to repolarize the generator as I've read in a few other threads? I'm not too good with electrical stuff, but it doesn't seem like a very complicated setup on the Cub, so I'm hoping I can figure it out with a little help.

Did you have the battery disconnected while at Barnyard’s? Try repolarizing.

[Glen]

Hi,
Good that you and the others fixed the brake.
Below is a page from the 1955 Cub operator's manual telling how to polarize the charging system.
I think they didn't have this info in the first few years of owner's manuals.
IH was using the voltage regulator in 1955. Jim B. has said it is the same method to polarize the cutout, or Relay system.
You will have to identify the wire connections. The Relay is originally on top of the generator.
Use a light and a small mirror up under the hood from the left side to find the posts.
The posts should be marked.

https://farmallcub.com/rudi_cub/www.cle ... age-35.jpg

Below is the trouble shooting chart that has been on here for the cutout, or Relay IH called it, system.
Use only the upper chart, 7, for the Relay system.

[cdahl383]

I did remove the battery when we drove there and then re-installed once we arrived. I never really checked the charging system after that as I was just moving the tractor in and out of the barn.

I'll read the trouble shooting guide, but why do you have to repolarize the generator? Is that something that must be done every time you unhook the battery or no? I've had the battery unhooked several times before since buying the tractor and haven't run into any issues. Is it sort of an intermittent issue when unhooking the battery?

[Don McCombs]

Having the battery disconnected for the time period described, would not normally require repolarization. BUT, electricity is magic and therefore unpredictable. Try repolarizing. If it doesn’t work, go to the troubleshooting charts.

[cdahl383]

Having the battery disconnected for the time period described, would not normally require repolarization. BUT, electricity is magic and therefore unpredictable. Try repolarizing. If it doesn’t work, go to the troubleshooting charts.

Ok thanks! I'll give that a try one day soon and see if that helps.

[cdahl383]

Had the tractor out for a little bit today on my lunch break. Fixed a couple minor things and wanted to take it out in the yard. It wasn't charging when I took it out of the garage. As I was driving it around in the yard, I noticed the amp meter showing 2amps. I switched it to High and it went up to 10amps! Apparently it fixed itself somehow.

I was thinking about it more and the only thing I can think of is when I oiled the fan hub at the Cub Fest, I probably got some oil on the belt, and maybe that caused it to slip? Maybe it wasn't turning the pulley on the generator enough to register a charge?

It seemed like when I ran it at higher RPM it was charging fine. When I set the idle down really low to get off the tractor for a bit, it stopped charging completely again. I got on it and got moving and got the RPM's up higher again and it started charging again just fine. Maybe there's a little residual oil still on the belt that's causing it to slip a little? That should burn off after some more use.

It's either that or a loose wire that's got a bad connection. But it seems to be attributable to the engine RPM. There's lots of oil in that area from the mess oiling the fan hub made. Maybe I lucked out and that's all it is. I'll keep an eye on it over the next few times I take it out.

[staninlowerAL]

If you decide to adjust the belt tension between the CS pulley and the pulley on the fan shaft, DON'T TURN THE NUT ON THE FAN SHAFT TO LOOSEN IT!! It's designed to be loosened by turning the fan shaft rather than the nut on the shaft (the shaft is made for an open end wrench). You run the risk of breaking the forks that hold the assembly to the front engine cover because the nut fits in a slot in the forks which is made of cast material. JMHO Stan

[cdahl383]

If you decide to adjust the belt tension between the CS pulley and the pulley on the fan shaft, DON'T TURN THE NUT ON THE FAN SHAFT TO LOOSEN IT!! It's designed to be loosened by turning the fan shaft rather than the nut on the shaft (the shaft is made for an open end wrench). You run the risk of breaking the forks that hold the assembly to the front engine cover because the nut fits in a slot in the forks which is made of cast material. JMHO Stan

I had a couple people tell me that at the Cub Fest. That seems like a very easy mistake to make as you would assume to adjust the nut. I think for now it's okay. I'm just glad it's working properly.

[Jim Becker]

A charging problem that comes and goes is often caused by a dirty or loose connection. If the problem comes up again, that is where to look. However, if your problem is only lack of charge at low idle, you don't have a problem. It is completely normal for the charge rate to drop to or near to zero at idle.

[cdahl383]

A charging problem that comes and goes is often caused by a dirty or loose connection. If the problem comes up again, that is where to look. However, if your problem is only lack of charge at low idle, you don't have a problem. It is completely normal for the charge rate to drop to or near to zero at idle.

I'll keep an eye on it. If it seems sporadic I'll check the connections. It seems to just stop charging at lower RPM's. Maybe it was always like that and I never noticed.