12 volt back to 6 volt?

[JustJim]

Well, I've done it now - have agreed to buy two Cubs, one running and one partially disassembled. They've both been converted to 12 volts, but because I like things all original (and perhaps because I'm weird), I'm considering restoring the older project tractor to 6 volt electrical system.

As it sits, it has no battery and the 6 volt starter had been removed, so it may not be functional. This is a magneto ignition Cub, and is supposed to be a 1952. I'll know more when I get them home, but what might be involved in restoring 6 volt operation? I know I'll need a generator (and bracket?) and voltage regulator or cut out, but it won't surprise me to find the wiring harness in need of replacement, so now seems to be the time to change things over if I'm going to.

Any thoughts? Cautions? Anyone care to suggest I seek out a mental health professional?

[Urbish]

There's nothing wrong with 6V as long as you use heavy battery cables and have good connections. Three of my Farmalls are 6V (one magneto, two battery ignition) and they work great. You will need generator & bracket, cut out, and battery. Ammeter should be tested and can be used if it works and is a low range one (-10 to +10A). If it has lights, you might have to swap out the bulbs.

[Jim Becker]

I converted one from 12 volts to 6. When I got it the alternator wasn't working and I had a 6-volt generator on a shelf. The wiring harness had multiple Super 33 upgrades that needed to be addressed as well.

Most Cubs from mid-1950 on came with battery ignition. So a '52 with a magneto seems unlikely. If you set it up with a generator and regulator, you will also need a regulator mounting bracket.

[JustJim]

Yeah, I'm just repeating what I was told on the date. Neither tractor had a data plate I could read, and the shed they are stored in was a bit too dark to see details. First step when I get them home is to spray the really bad areas with engine cleaner, then go over them lightly with a pressure washer.

The older, non-running tractor has a hood/tank that looks really good except for being covered in "schmutz." I don't know if it received some attention previously, or if it might have some nice "work clothes" under all of the dried oil and dirt. I'm going to take care to not clean it too aggressively until I can see what I have.

Thanks for suggesting a look at the ammeter and headlight lamps!

[Glen]

Hi,
I would use a good light and try to see the serial numbers of the Cubs.

IH changed to the voltage regulator system, and 3 position light switch, at Cub serial number 115403, which was during 1950.
Before that they used the cutout, or Relay IH called it, on top of the gen, and the 4 position charge and light switch.
The Battery Ignition unit came out at 115403 also, and lots of Cubs had it, I think.

The voltage regulator is on a mounting bracket beside the gen.

The wiring harnesses are different for the 2 systems.

Below are pages from Cub owner's and operator's manuals showing the 2 systems.
The 1st pic is the older system.
The 2nd pic is the newer system.

http://farmallcub.com/rudi_cub/www.clea ... age-33.jpg

http://farmallcub.com/rudi_cub/www.clea ... e%2050.jpg

[NJ Farmer]

Welcome back to the 6 volt world!! There are plenty of parts and spares since everyone trashes 6v starters and generators. Frankly for a tractor I never needed 12 volts to keep up with the major draw load of the distributor.

Just a tips as stated before…..running a good 6 volt system requires that you do have good ground connections. Personally I like to wire brush all my ground connections then use Dow-Corning 4 silicone grease to prevent any corrosion from taking over especially on generator and voltage regulator connections. Been working for me over 25 years and never EVER had a problem.

Corrosion is the 6 volt system arch enemy which causes bad grounds (or grounding).
NJ Farmer

[JustJim]

Thanks again gents!

As stated, I don't have the Cubs yet, but I brought home a load of implement parts and a few loose components from the disassembled tractor. I took the starter apart and cleaned it up today. It was sitting loose on the seat of the tractor, so I suspect the starters had been swapped between the two.

The commutator showed copper bridging between the segments. This has now been cleaned out and the mica insulators cut back. The brushes looked passable and the bushings seemed okay, so it's clean, lubed and reassembled. I'll test it tomorrow, just wish I had a 6 volt battery to test with. Perhaps I'll see if I can pick one up in town - then I'll be committed, I guess!

[NJ Farmer]

What is nice about generators is the simplicity and strong durability. They are built to last beyond my lifetime….

NJ Farmer

[k hutchins]

Hello
I too tend to be an "originalist". I recently bought a '48 that had a distributor on it. Long story short l got a mag and converted everything back to original.
As far as new wire harnesses go, l made up two new ones. One for the new '48 and one for my original '48. I used #10 for the main wires and #12 for the cut off switch, headlights, and short links around the generator and light switch.

This is the best diagram l found to go by. There's a lot more info here on the forum if you need it.

Good luck
We're here to help if you need it.

[BigBill]

I had late 40’s and early 50’s Chevy 6 v trucks. They turn over so slow in the winter you think there not going to start. The trick is having a good quality battery and keep it tuned correctly.

[JustJim]

Thanks again fellows! And thanks for the good wiring harness diagram.

I did buy a 6 volt battery from Napa, so I'm committed. I wanted it to test the starter I have been working on, but sadly, it refuses to cooperate. Now I will need a starter as we!l as a generator, etc. There's another Cub close to me that will probably never run - too much time uncovered in our rainy weather - but it has a Woods mower and would probably cost me less than wrangling a starter and generator from eBay. Hmmm... I begin to understand why so many of you have multiple Cubs!

[outdoors4evr]

Why buy a new starter? Have yours rebuilt by a starter shop. Here's one near your zip. No idea on their quality or price.
Aaron's Alternator & Starter Service
472 N Main St Ellijay, GA 30540-3306 (706) 635-1257

[JustJim]

Now there you go, killing my excuse to pick up another Cub!

Honestly, I didn’t spot that shop when I did a recent search. I’ll go talk to the guy and see what he has to say.

[Jim Becker]

Why buy a new starter? Have yours rebuilt by a starter shop. Here's one near your zip. No idea on their quality or price.
Aaron's Alternator & Starter Service
472 N Main St Ellijay, GA 30540-3306 (706) 635-1257

I'm not sure that is still there.

[tldec50]

Jim,Southern auto electric morland ave in Conley,ga just off I-285 has rebuilt my starter generator,cub starter,and mf35 starter and 2 j.d. starters. He does good work.Maybe a 75 mile drive from you if you do not find someone closer.