Farmall Cub

In the process of putting my Super A back together and I notice in the exploded diagram that there were 2 type of voltage regulators. One mounted beneath the generator on the bracket and the other mounted on the generator in a saddle-type mount. The generator had the 2 threaded holes that the saddle mount attached with so I bought one of those. Question is, what is the difference in the 2 and will the setup I have bought work? Thanks in advance.

Phillip

I believe the generator mount one is actually a cutout not a regulator if you check the parts list. Even so, you can still use a saddle mount regulator. Connect f lead of gen to F term of regulator, and A lead of the gen to Gen lead of regulator, and bat. terminal of regulator to the battery lead. If it has a lead that went from F of gen to headlight switch, disconnect it.

Thanks John. Was just reading some of your posts on this issue. Will it matter if I have a 3 position or 4 position light switch? I also am going to make sure it is a cutout and not a VR by pulling the cover. When I got this Super A it had a 12 V conversion and alternator. Wanted to restore to completely factory with the exception of an 8 volt battery like I did my WW 2 jeep and Dodge. Going to the shop to check the switch and cutout now. Just finished painting today. Hope to be able to post some pics of the restore process soon.
Phillip

It is a Voltage Regulator as it has 2 coils under the cover. Left to right terminals are: 'L', 'BAT', and 'F' with what appears to be a tall voltage resister. Underneath is the 'GEN' lug. The light switch is a 3 position. It will be negative ground. Is there anything that I should be aware of?

Phillip

I would not use the 8 volt battery. If your connections are good and starter is healthy it will crank nicely with a 6 v.

Al

If you are going original it would be a + ground system. Unless you have an 8 volt regulator you will not gain anything using an 8 volt battery, as it will never be fully charged. If you had the old manual charge control system using the 4 position light switch, and the cutout, an 8 volt battery may improve cranking some, but not much gain with a regulator.

Thanks. I did not know that about the 8 volt not being fully charged. Do I need to do anything except reverse the 2 main battery cables? And what was the purpose of positive ground? Mack fire trucks used to be positive ground. The main thing is that I don't want to fry my new VR.

Phillip

Probably will also need to reverse the ammeter connections also. Was your new regulator marked positive ground or negative ground. If no markings it should work either way. All of the old 6 volt equipment I have ever seen was + ground. That is the way electrical stuff all started so far as I know. The change to - ground came about as more electronics started being added, first transistor radios, then more, up to the computerized cars. The tractor will start and run fine, no matter which way the battery is hooked up, but do not forget to polarize the generator.

When I mentioned the saddle mount unit being a cutout I was referring to what would have originally been on the generator you bought.

8v battery more headache than help. BTDT with old Chevy truck. IMHO, stay 6v or go to 12v one wire alternator.

Thanks guys.

Phillip

Thanks for that info on the 8v battery. I have a friend you has been having problems with his 8N and he has an 8v battery in it.

Allen

You could also get a Delco alternator set up for 6v neg. ground. A lot of A model Fords are running them.

Snowdad,
Looking at the SA parts catalog TC-39C, both cut-out relay and voltage regulator were used. The diagram shows the cut-out mounted atop the generator like a Cub and the regulator mounted below the generator on the bracket. The cut-out will have 3 connections and one coil and the regulator 4 connections and two coils. My SA has a 3 position switch but I guess the ones that used the cut-out used a 4 position switch like the Cub since the parts catalog calls out a different switch for use with the cut-out. Since the cut-out system didn't regulate the voltage, the extra switch position was to increase the field current of the generator where the operator could switch between low charge and high charge for the battery.
On polarity, the 6v regulators were designed for positive ground. From the Delco service bulletin IR-116 page 4:
"Some regulators are designed for use with negative grounded batteries while other regulators are designed for use with positive grounded batteries. Using the wrong polarity regulator on an installation will cause the regulator contact points to pit badly and give very short life."
On the 8v battery, make sure your battery leads are the correct gauge if ever changed, keep the terminals tight and bright and you'll never have a problem with a 6v system, not anymore than a 12v system.
If you have a 3 position switch, you should use a voltage regulator and wiring diagrams are on the web. If you need the diagram, let me know.
Gerry