6v or 12v generator?

[Zachary Hoyt]

I am trying to figure out if my charging system works on my C. It came with a swelled up 12v battery on it, with the - side grounded under the steering wheel. I took the bad battery off and put a battery on it and the starter worked fine. The generator looks clean inside and is not obviously damaged. There is a wire that runs from the relay or voltage regulator box on the generator to an ammeter and then comes out again and has been cut off at that point. I am guessing the previous owner used a battery and then charged it occasionally. I don't know where that cut wire should have gone, or how to tell if the generator is 6 or 12. I would like to buy a new battery if I knew which kind. I'll try to post pictures. I put on a muffler and it is touching the underside of the hood. I have tapped it on with a mallet and it doesn't seem to want to go further. Is is a problem that it touches? Thanks very much for putting up with all of my questions.
Zach
Zach

 

[Zachary Hoyt]

Here is photo #2. I can't seem to get them both in one.

 

[steve(ill)]

that looks like a 6 volt generator. the "F" terminal is the ground and goes thru the head light switch to ground. the "A" wire goes to the cuuout realy box in the photo The output of the cutout goes to the amp guage. other side of the amp gauge goes to the battery negative terminal. system was positive ground when new. If the generator works (6 volts), you could put a 12 volt voltage regulator on it and get a couple amps trickle charge at 12 volts. you can use + or - ground, dont matter. more questions?

 

[Zachary Hoyt]

Thank you very much. The wire that is not connected to the cutout relay goes from one point on the generator to another and I am not sure which one is the F terminal or where to ground that wire. What I think I am reading in your response is that the generator will work for either 6 or 12 and for either type of ground. If I understood that right would it be better to use 6 or 12? All that I have in the system is the generator, battery, ammeter and starter, so I don't have a lot of draw on the system. Thanks again for your help.
Zach

 

[John T]

Its likely a 6 volt but I cant say for sure...

Looks to me like it has the gennys FLD post permanently grounded to the gennys case which would allow it to always charge in the MAX HIGH charge condition which could overcharge n harm the battery if it was ran at high RPM for long time periods with no lights being used. (i.e. the genny post that wires to its case is its FLD post)

The gennys FLD post was probably permanently grounded because the Low/High charge control light switch wasnt there or went bad. When present and working the gennys FLD post (instead of jury rigged grounded at genny as shown in picture) wired to the light switch where it could be set for Low or High charge.

The other (NOT one to case ground) genny post is the ARM post and it wires to the (GEN/ARM) side of the cutout relay. The other (BAT) terminal on the Cutout Relay wires to the Load (NOT battery/starter) side of the ammeter. the other (Supply) side of the ammeter gets to the hot ungrounded battery post often via a connection to where the big battery cable attaches to a starter switch

I suggest DO NOT use a 6 volt genny at 12 volts. Sure, it can be used to charge at 12 volts if a 12 volt Voltage Regulator were installed (Ive done it) but its not any high charge rate plus the gennys Field windings can draw more current then designed for and possibly overheat. A genny repair shop can change it over with 12 volt field coils if you want to do it right and again it can work at 12 volts if its a 6 volt genny but its NOT engineering correct.

Got it ????????????

John T

 

[Zachary Hoyt]

John, thank you very much for taking time to describe all of that. Now I have some understanding of how it's supposed to work. I bought a 6V battery today and will put it on soon. The tractor has only one light and it doesn't look to be usable. Is there a way to wire a high/low charging switch into the FLD wire without having lights on the tractor, or is there another way to keep it from overcharging? I would hate to ruin a new battery. Thank you again.
Zach

 

[chalmersbob(Pa)]

the left hole in the dash box is for the light switch. You may as well buy a regulator as the light switch will cost more then the reg. If you look real close at the genny, you will see rhe letter "F" next to the field post and the letter "A" next to the generator output post. With a regulator, the "F" wire goes to "F" on reg "G" wire goes to "GEN" on reg and the battery wire, the one that comes from the amp meter, goes on the "BAT" terminal. If the reg has a "L" terminal, it doesn't get used. I would stay with 6 volts. With clean grounds and battery terminals it will work fine. Bob

 

[John T]

Youre welcome, Sure, it may be easier to just buy the readily available n relatively inexpensive original Light switch that has Low and High charge settings even if you dont bother to hook any light to its light terminal. It has a terminal that wires to the FLD post on the genny (versus its being tied to ground as in the picture) and has an on board resistor used for low charge, make sure it has a good ground (perhaps just to the dash via its mounting there).

In the alternative buy a single pole double throw (SPDT) Toggle Switch and wire its common center THROW terminal to the gennys FLD post..........wire its High Charge (Pole) dead to frame ground........wire its other Low Charge (Pole) to ground via an in line series 2.5 to 3 ohm or so 25 watt power resistor. Then after start up leave it in high (dead grounded Field) charge for 15 to 30 minutes or so and then switch to Low charge (field grounded through the 2.5 to 3 ohm resistor) rest of the time unless youre using lights then leave it in high charge, which is what the original low high charge light switch does.

John T

 

[Zachary Hoyt]

Thank you very much. If I ask for a 6v regulator are there other specs I will need to know to buy the right one? It sounds very easy to install.
Zach

 

[Al L. in Wisc.]

I"ve got to get in on this one as my "55 CA six volt system, has either a regulator or cutout - just two connections and the generator is wired to ground w/no fuse in switch box. What is the difference between the two? Brittle/fraid wires are going to get replaced, what gauge would be best? Thanks in advance for any input.