generator

I just bought a Farmall C and the generator does not work. I had the generator rebuilt and got the wiring diagram for it.on the wiring diagram it shows 4 connections on the regulator[gen., batt,field and L.] and my regulator only has 3 connections on it. It does not have the L connection on it. My question is, is there a way to wire this so it works? Any help will be great Bill

The "L" connection was for lights and it had slightly higher voltage for brighter lights. You can disregard it and connect your battery(thru the ammeter) to the "Bat" connection. The "F" or field connection and the "A" armature connections go to the apprpriate connections on your generator.

Yes, pretty common conversion. Just put both the L and BAT wires on the BAT terminal of the regulator.

Make sure the generator is properly polarized. Some one can give you directions. I have to call my generator/alternator/starter man when I have to do it.

Dad always said, if you have three contacts, TOUCH a jumper wire between any two, and if you get a spark, it"s polarized.

The "L" terminal on the regulator is for an idiot lite. It's not hooked to anything on your tractor.

The "A" terminal is your output to your battery. That wire should be hot all the time. The "F" terminal is your field terminal. When this terminal gets grounded the generator begins to charge. The regulator regulates how much current goes thru this circuit which allows the generator to charge hi or low. You have to make sure your generator is well grounded to the frame and bracket to the frame. I've run a seperate ground wire to generators before to make sure they're grounded. The regulator has to be properly grounded to work also. To polarize the regulator to the generator, hook the regulator up with battery connected, take a short jumper wire and hold it on the battery terminal of the regulator and just swipe the other end of your jumper wire over the "A" or "Gen" terminal of the regulator. Now with this done, run the tractor at 3/4 throttle and if it still doesn't charge ground your "F" terminal on the regulator to the battery ground. This full fields the generator which should make it charge to its max. I know this sounds a little complicated but take one step at a time and check each circuit independately.

Bill, YES it can be converted and used, heres how:

1) In the event your old wiring utilized a 4 terminal VR that had the L load terminal, the wire that used to go to the L can now be wired instead to the BAT terminal on the new VR along with the other wire on BAT that wires up to the load (NOT battery/starter) side of ammeter.

BAT on VR up to load (NOT battery/starter) side
of ammeter

ARM/GEN on VR to gennys ARM post

FLD on VR to Gennys FLD post

2) The wire that used to connect to L load on an old 4 terminal VR (if it had one) can be wired instead to the Load (NOT battery/starter) side of ammeter, the same ammeter terminal that wires down to BAT on the VR.

BAT to ammeter
GEN/ARM to gennys ARM post
FLD on VR to gennys FLD post

If it used an L terminal connection on an old 4 wire VR that supplied hot battery voltage to loads like lights and ignition. If you only have now a 3 terminal VR those loads not get voltage off the load side of the ammeter, same side that wires down to BAT on the VR. Thats why if the wire that used to go to L is wired over to BAT on the VR (along with other wire there up to ammeter) it will work

If it had a 3 terminal VR before all this, the loads should already be fed off the ammeter so all you have to do is wire BAT and FLD and ARM on the VR as described above

Any questions???

BE SURE TO POLARIZE THE GENNY BEFOREEEEEEEE START UP

John T

John, with all due respect NOT to argue Im ONLY here to try and help,,,,,,,,,you stated The "A" terminal is your output to your battery. That wire should be hot all the time.""

I think maybe your fingers got ahead of your brain, hey dont feel bad happens to me all the time lol

ACTUALLY on a VR the BAT is the output up to the battery and ittttttt should be hot all the time as its wired to the hot battery terminal via the ammeter.........The ARM or A or GEN terminal on a VR is wired to the gennys ARM output post AND ITS HOT ONLY WHEN THE GENNY IS TURNING AND IF ITS WORKING AND NOTTTTTTTTTTTTTTTTTT ALL THE TIME AS YOU STATED

Now if a genny is working and turning, at a certain voltage output on the genny when it exceeds battery voltage the cutout relay (between GEN and BAT) will latch closed and then the output of genny will be connected to the batetry to charge it (via ammeter) but when the genny stops the relay opens and the ARM is no looger hot all the time, only the BAT terminal on the VR remaons always hot

Hope this helps, best wishes n God Bless

John T

Listen to John T, not John B.

Sorry (with respect) the L terminal on generator based delco system regulators of the vintage being discussedm, is a Load connection to be attached to the light switch light supply terminal, and or Key. It is hot all the time, and is not as carefully regulated as the Batt terminal which is connected to the amp gauge load side.

Hooking a light to it would be permanently on. We have been around these old mechanical piles of windings and circuits for 55 or more years. Jim

The load terminal is as stated, for the load, which lights is the main one. Ignition was often hooked through that also. The purpose of the load terminal is that the regulator is a combination voltage and current regulator. By using a seperate load terminal that current is not regulated therefore the current regulating winding can still allow enough regulated current to charge up a battery if need be. The original three brush generators were only about 15 amps out put but later ones were more like 25 and then the last ones were shunt wound generators with about 35 amps available. In other words you can regulate maybe 15 amps which is about the capacity of that set up but still utilize about 30 amps of charge from generator. Clear as mud right. The book does a lot better explanation than I can but haven't read up on it lately. The three unit regulator they went to on the last model tractors with generators did a much better job of regulating in all respects.

(quoted from post at 14:06:54 06/08/12) The load terminal is as stated, for the load, which lights is the main one. Ignition was often hooked through that also. The purpose of the load terminal is that the regulator is a combination voltage and current regulator. By using a seperate load terminal that current is not regulated therefore the current regulating winding can still allow enough regulated current to charge up a battery if need be. The original three brush generators were only about 15 amps out put but later ones were more like 25 and then the last ones were shunt wound generators with about 35 amps available. In other words you can regulate maybe 15 amps which is about the capacity of that set up but still utilize about 30 amps of charge from generator. Clear as mud right. The book does a lot better explanation than I can but haven't read up on it lately. The three unit regulator they went to on the last model tractors with generators did a much better job of regulating in all respects.

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ery good Pete! Haven't seen any poster in years come as close as you did with that explanation.

Your dad was incorrect. The only hot wire comes from the battery. If brushed aont the field, it will sure spark, but it is directly to ground on these systems. the Voltage regulator points (not cutout would recieve a direct assult and might just weld together. If from Bat to Gen (or ARM) it will do as intended.
If it was a B circuit (Ford type) flashing the Gen to Field would be correct. It is not one size fits all. With respect, and to reduce chances for failure/damage. Jim

Your regulator must be original and is wired Batt terminal goes to the ammeter which would be 6v The gen terminal on the reg goes to the A term on the gen and the field on the reg goes to the F on the gen there was no "L" on the original reg so dont worry about that wiring dia as it is not how they were originaly wired. Does your reg mount below the gen as that was the original mount on later Cs early models had a cut-out on top of the gen. Dont know where you found that wiring dia as it is not the way they came from factory. I like to keep things original as they just work. Does your gen still have the tag and what are the numbers. Its probably a 1101501

OK here's where I'm at.completely confused. can't find any numbers on gen, the gen has 3 brushes??, there are 2 wires in the wireing harness to the reg. I'm thinking this is the original gen and somebody replaced the cutout with a regulator. Whats the differance between a reg and cutout. it mounts on top. I found the wiring dia on this site, under manuals altho its for an H. I assumed they'ed be the same,no Bill