Farmall cub 6 volt will not charge wiring problems

[Dvss1]

Hi all,
Just picked up this cub. Serial #5891. This is 6 volt with a magneto. When I got this it wouldn't charge. I looked at the harness and battery cables and most of the insulation on them all were deteriorated so I bought new ones and installed. So I got her to run but still no charging. So I checked the generator and did the battery to generator test and it did spin. Then I did check the regulator and it does check out. I also did the polarity test since the cables on the battery were negative ground and I changed it back to positive ground. I've looked at a couple of wiring diagrams on the site and wired it to the diagram. One thing that is wired is if I hook the light wire up to the regulator, the light switch begins to smoke!! I also connected the wire with its running turn the light switch on to any indent and it burries the gauge over to the discharge side. I can get it to run, take off both battery cables and it still will run, just can't get it to charge not can I get any of the lights to work. Any help will greatly be appreciated. I've also added some pics. Thanks guys

[Bill V in Md]

Based on the serial number of Cub, I assume you have a four position light switch. Those have a wire wound resistor that controls the dimming function of the lights. Sometimes the old insulation on the resistor will smoke, and this may be what's happening. On the other hand, this switch controls the charging and maybe it is wired incorrectly. Recheck the wiring connections at the switch, amp meter, generator and regulator. Your cub came from the factory with a cutout relay (not a voltage regulator), but maybe someone changed it to a voltage regulator.

You could troubleshoot the functionality of the lights by connecting a jumper wire from the battery hot post directly to one of the headlights (where the wiring connects). If the light bulbs are good, and light does not work when you do this, your lights may not be grounding properly through the light housing.

[Jim Becker]

That tractor would have originally had a cut-out rather than a voltage regulator. Has it been changed to a regulator (typically square with 4 connectors rather than rectangular with 3 connectors)?

Smoke and heavy discharge sounds like a bad light switch or maybe shorted wire at the switch. A wrong connection could cause it too.

Magneto is totally separate from any other electrical equipment. Disconnecting anything in the starting/charging/lighting systems will have no effect on keeping the engine running.

Disconnecting a battery while the engine is running is a dangerous action and doesn't provide any information that can't be found safely. Don't do it.

Have you tried directly grounding the generator "F" terminal to see if it starts charging?

Have you checked all electrical components for a good ground (including the light switch)?

[tst]

can you post a picture of the generator/regulator so we can see what you have

[Dvss1]

Yes, someone changed the cutout to a regulator. I will post some pics when I get home. For some reason the pics are too big comming off my phone.

[tst]

if you have a regulator setup and it is wired correctly here is a flow chart to help diag the problem

[Glen]

Hi,
The Cub operator's manual can help you learn about maintenance that the Cub needs.

Below is the 1947 Cub operator's manual. The experts on here recommend people read it. It has lots of info about operation, maintenance, and lubrication.
There is a table of contents on page 1, and an index on page 62.
It shows how Cubs originally looked in it. The lube section begins on page 14.

http://farmallcub.com/rudi_cub/www.clea ... index.html

This manual shows the electrical system that a 1947 Cub originally had.
Cubs made before mid 1964 originally had 6 volt, positive ground electrical systems.

There is no info in it for the Touch Control, info for that is in newer operator's manuals, including checking and changing the fluid, and removing the air from the system.
The Touch Control uses Case IH Hy-Tran fluid. It is sold at Case IH dealers.

I would check or change all the oils before using the Cub. Using it with low oil in a gear housing can damage the parts in the housing.
There are 3 separate gear housings, with 3 separate oil levels to check, in the rear area of a Cub, the transmission, and 2 final drives.

The transmissions in Cubs commonly get water in them, from rain, or condensation inside the housing over time.

[Dvss1]

Hi, here are the pics. I did ground the f terminal and it did not charge. I also did a continuity test and I have good continuity. Now since this originally had a cut out, can I use this light switch.
I did call the previous owner and he told me that they had the starter and generator rebuilt. They also put the regulator and could never get it to charge nor could they get power to the lights. I do show the harness that was on it when I bought it. I dont know why they didnt change it. I think I have everything connect correctly. If some sees something I dont have correctly connected, please let me know.
Thanks Guys!

[Dvss1]

More pics

[Jim Becker]

From what I can see, the wiring looks OK. I assume the black wire off the ammeter goes to the big lug on the starter. I didn't check wire locations on the light switch.

Connect a voltmeter from the generator A terminal to ground and see what you get. Ground the "F" and try it again.

[Dvss1]

Since getting this 2 weeks ago, I have changed engine oil and filter, drained the transmission rear end and put fresh oil in. Greased all the fittings I could find. I've drained and filled one side of the lower rear. The other side, I have to take off the link off the back which I will get to next weekend. I've also changed wiring harness, both battery cables, cable from switch to magneto and changed the rear light harness, plugs, wires, cap and rotor. Oh yes I installed a battery too

[Dvss1]

I would like to do the flow chart test, but I need to figure out where to install the white black stripe wire to. I have one end hooked to the light switch and like I stated before, when I connect it to the regulator the light switch begins to smoke. Can you take the light switch apart? Also can you use this light switch with a regulator?

[Jim Becker]

Your light switch already has a power feed directly from the ammeter. You don't need the white/black wire. You may have it connected to the wrong place. There is a resistor on the light switch. You may just be burning accumulated trash off the resistor. You can use this switch with a regulator. The separate low/high positions are no longer used. They are both just "off".

[Nelson 634]

Did he polarize the generator? And is he using a digital or analog meter for checking? I am correct? the analog is generally better for six volt cub work right. Walter

[Glen]

Hi,
Thanks for the pics. The Cub looks good.

The model number of the generator, on the plate, is what a 1947 Cub came with.
The serial number, on the right side of the plate is a code, it shows the gen was made in a year ending in 7.
The D is a month code, so it was made in April.
The 10 is the day of the month it was made.

Yes, the original 4 position charge and light switches come apart, they have screws holding them together. It can be cleaned inside, if you take it apart.

If you have the wiring connected right, and it won't charge when you ground the Field connection, the gen may have a problem. You could remove the band from it, and look in it with a good light. The brushes have to be good, not wornout, and the commutator has to be clean, which is copper colored, not dirty.

I saw in one of your pics that the seat post mounting, at the base, has a wrong bolt in it.
The Cub parts manual says it should have 5/8" x 1 1/4" long bolts, and lock washers.
Be sure the seat is fastened on properly before using the Cub, and that parts are not rusted so much that they are unsafe.
Below is the parts manual page. The bolt info is at number 9 in the description.

http://www.farmallcub.info/manuals/cub_ ... 013-10.jpg

I saw in one of your pics, it looks like there is no throwout bearing holder upper pin sticking out of the small hole in the clutch housing, on the right side of the Cub.
I don't know if you have the pin out, or it has none.
It could be sticking out the left side of the housing.
The clutch can't work without the pin in place. It holds the throwout bearing holder in place.
There should be the end of a pin, and a cotter key there, on both sides of the Cub.

Below is a listing at TM Tractor for a new pin, you can look at the pic.

http://www.tmtractor.com/new/cl/5327fp.htm

Below is a pic of a Cub that is split, you can see the throwout bearing, the holder, and the pin at the top of the holder.