B Farmall Charging system

I have a B farmall and I am having trouble with the charging system the Amp gauge does not show it is charging until the tractor is reved to 3/4 throttle it there any adjustments you can maker so it charges at a lower rpm also. Thanks

Hello Blair welcome to YT! Is it the stock 6 volt system
with the generator? Or has it been converted to a 12
volt with an alternator?

that is pretty much the way the 6 volt systems work. at idle they do not charge. but at 3/4 throttle they should be putting out. yes you can
set the regulator up. but its best with a manual in this case as it just takes a slight screw movement. ... not turns! i cant upload a
picture to help you.

(quoted from post at 18:20:32 09/15/22) Hello Blair welcome to YT! Is it the stock 6 volt system
with the generator? Or has it been converted to a 12
volt with an alternator?

Click to expand...

It is a 6 volt system

Ok,so you can adjust that on the regulator or is that way it is?

I have another question to, I read online that that you have to have a two brush generator with regulator and a three brush generator with a cutout. I believe this tractor has a a 3 brush generator with a regulator is this possible for it to even work at all if that is true!

Adjust the third brush on the gen to get more out-put. Loosen the screw head
on the brush end then you can adjust the third brush moving that brush closer
to the next brush will increase the amps unless the brushes need to be
replaced and the commutator needs the slots cleaned and the surface cleaned
What is the delco # on the gen regulators were made to replace the cut-outs if
the correct one was installed is the #1101355 or 1101423 on the gen

no you adjust the third brush on the generator you dont mess with the
regulator you must have the correct one or it wouldnt charge what is the volts
on the battery when engine is running

Those systems can be complicated and cantankerous to keep working.

If yours is working, and charging at the correct voltage, count your blessings and LEAVE IT ALONE!!!

But if you want to tinker with it, take pictures, make notes, measure every step, so you can return to where you started if need arises!

Some things to keep in mind, if it does have a regulator (not just a cutout) do everything you can to save it! New aftermarkets are near worthless, nothing like the originals that had high grade expensive alloys in the contacts, and were carefully fit to the exact specs of the generator output.

When adjusting a regulator, the cover needs to be sat back on after any adjustment, it will change the settings, messes with the magnetic field somehow. If you make adjustments to the regulator, you will need a quality analog volt meter, like a Simpson, not a Chinese pocket meter!

If it has only a cutout, there is a solid state diode type that replaces it. Never tried one but the theory makes sense.

Here is some information on 3rd brush generator systems and generators in general.
Generators

Yours is NOT the only one Ive seen act that way when I was a used tractor dealer.

If you were to use a jumper wire to dead ground the gennys FLD post when running at
high RPM that will show the max charge the genny is capable of WITHOUT RELYING ON
ANY REGULATION SYSTEM (VR or Manual Low High), thats it. If thats what it charges
when left on its own the genny is probably okay, but if less on its own, then there
may be a regulation system problem. If its a full fledged Voltage Regulator problems
may be its adjustment or relay/contacts or its ground,,,If its a Cutout Relay system
with Low High Light switch manual charge control scheme, the switch may not be well
grounded or bad or the wiring from FLD on genny up to Low High switch.

Some older 3 brush gennys had an adjustable third brush and if set/adjusted closer
to the main brush next to it the charge rate increases. I would check and insure the
Low High switch (up on dash) or VR (by generator) if so equipped has a good clean
ground connection.

Insure the belt is good n tight.......I dont get into any VR or Cutout Relay
adjustments over the net (other than perhaps lightly buff polish relay
contacts).........It may help to give the gennys commutator a good cleaning and
shining and if necessary undercut between segments to reduce brush
bounce.......CHECK ALL GROUNDS genny as well as Low High Switch or VR if so
equipped....... NOTE if the gennys brushes are worn down getting low could cause
problems and they should be replaced

Below is my Troubleshooting Procedure check it out

https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=ttalk&th=2060825

Did I mention CHECK ALL GROUNDS ??? Cutout Relay to Genny,,,,,,,,,,VR if so
equipped,,,,,,,,Low High Manual Switch,,,,,,,,Genny itself. If dead grounding the
genny still yields the same charging current as if nothing were done the genny is
likely okay so check all the other things I mentioned

John T
John Ts Troubleshooting

If the light switch has 4 positions L-H-D-B it was equipped with a cutout relay OEM. The cutout looks very much like a regulator, and even has a F terminal on
it. (usually not hooked up to anything if the tractor was equipped with lights OEM. The true regulator if equipped will have two internal relay looking things
inside it. A cutout will have only one. If the light switch is, as above, with 4 positions the first position Counter clockwise is low charge. All other
positions are full charge rate. The light switch is completely separated from the charge control inside the switch, and sends electricity to the lights in D and
H positions. The L and H positions provide a ground for the F terminal on the Gen. The L position grounds through a resistor, lowering the charge to about 4
amps at maybe 6.8 volts (at 3/4 throttle). the H position and D-B positions just plain ground the field, allowing it to charge as much as it can, probably should
be about 7 to 7.1 volts at high engine speeds. The field windings get electricity from the commutator 3rd brush and are grounded to complete the circuit. Jim