Farmall A charging questions

[43ford]

I have an A that has not been charging the battery. I have a three brush generator that motor tests ok.
The regulator is a two coil type and I have a three position switch. The switch works fine for dim and bright lights.
I have traced all of the charging wires which seem correctly connected.
I am not seeing any movement at the amp gauge when the engine is running except when the lights are turned on. ( amp gauge shows discharge).
I tried connecting the generator field terminal to a good ground and still had no charge indicating at the amp gauge and the battery voltage did not increase.
Do I have the correct components? Three brush generator and two coil regulator ?
All wiring terminals have been cleaned and soldered.
I appreciate any and all suggestions.

 

[Janicholson]

Welcome to YT. Your efforts have been in the right direction so far. Some further diagnosis is needed. If the regulator body is not grounded through its mount, or a supplemental ground to the engine, it won't work. If you ground the F terminal and measure the Arm terminal to ground voltage, it should show well above 7 volts. If it does, the generator is making enough voltage to latch the cutout relay in the regulator. With the engine off, the F terminal on the regulator (wire off) should show it to be grounded inside the regulator, and to the engine. Put the wire back on. If the Bat terminal on the regulator (engine off) shows battery voltage, that should be good as well, No voltage there is a bad wire or connection to the load side of the Ammeter. The big set of contacts in the regulator are on the cutout relay tower inside. If they are not closing you could use a small stick to push them closed while running at 1/2 throttle. If they stick shut (supposed to do that) and the system charges, the issue may be fixed by adjusting the gap of the cutout a little closer (very small amounts at a time) to get it to close automatically when running but open when the engine speed slows or stops. Remaining closed when shut off will let the smoke out of components. Get back to this thread with results from the above. Also find John T charging system in the link here. Jim

link

 

[Jim Becker]

All the diagnostic steps JAN outlined are the right direction to go. However, the 2-coil regulator and 3 position switch are not original to an A. They came along part way through Super A production. This brings up a question as to whether you have some mismatched components. A mismatched set may work okay, may work but not very well, or may not play together at all. Can you verify whether you have a generator with a fixed third brush or an adjustable one? If the original generator tag is on it, the number would be helpful.

 

[43ford]

Thanks gentlemen.
I will test futher as described.
All grounds test good. All wires tested good for continuity.
The third brush is adjustable. I moved the third brush to a a number of positions with out success.
Thank you!

 

[43ford]

Another question…
Adjusting the third brush for maximum generator output. Is maximum made by moving the third brush up? ( clockwise looking at the rear of the generator)?

 

[Jim Becker]

The adjustable brush means it is the original style for a cut-out system. The third brush is close to the brush that carries the output voltage and far from the ground brush. Move it as close as possible toward the one it is already nearest to for maximum output. I don't recall off the top of my head whether that is clockwise or not.

 

[560Dennis]

The units I have for the Farmall C with magneto ignition
three brushes generator, one coil cutout Relay, amp meter, single terminal push pull switch to magneto on off ,Four postion switch (low charge,high charge,llow beam lights ,high beams lights ).

 

[Janicholson]

The adjustable brush means it is the original style for a cut-out system. The third brush is close to the brush that carries the output voltage and far from the ground brush. Move it as close as possible toward the one it is already nearest to for maximum output. I don't recall off the top of my head whether that is clockwise or not.

Closest to the Fixed brush as it can get. Armature connected brush. Clockwise. Jim

 

[teddy52food]

Short the moveable brush to the brush close to it & try again.

 

[rustred]

well try the stupid simple first. on a few tractors i have, all i had to do is shine up the commutator with a piece of emery when the tractor was running. waa laa and it started charging. the brass gets kinda of a film on it from sitting. dont know if anyone has tryed this but its one thing i do first and sometime luck out. even when the brushes get worn they dont have enough pressure on the commutator to make it charge. this is the most important things to check out . dont even have to remove the generator.

 

[43ford]

I have had some time to test/diagnose a little more. First off, I have a 4 position light switch. Not three position as I previously thought.
I have been able to motor test the generator successfully again. and while motoring the generator if I ground the field the generator slows down it's motoring rotation. With the field wire off the generator, motor running at about 3/4 throttle, when I temporarily ground the generator field terminal I get no voltage present at the generator A terminal. In addition the cutout coil never closes its points, ( field connected to regulator or disconnected and field manually grounded). I have retraced the wiring but need a circuit diagram for what components I have here. Photo's would be helpful also. I also disassembled the four position switch to make sure it was clean at its contacts. Both resistors on the light switch ohm test good.
I don't use this tractor much and am thinking that I could just go back to the original 3 brush and cutout system to lessen the complexity of its charging system. This tractor does have lights but I nearly never operate at dark.
What am I missing? Thanks

 

[Janicholson]

I have had some time to test/diagnose a little more. First off, I have a 4 position light switch. Not three position as I previously thought.
I have been able to motor test the generator successfully again. and while motoring the generator if I ground the field the generator slows down it's motoring rotation. With the field wire off the generator, motor running at about 3/4 throttle, when I temporarily ground the generator field terminal I get no voltage present at the generator A terminal. In addition the cutout coil never closes its points, ( field connected to regulator or disconnected and field manually grounded). I have retraced the wiring but need a circuit diagram for what components I have here. Photo's would be helpful also. I also disassembled the four position switch to make sure it was clean at its contacts. Both resistors on the light switch ohm test good.
I don't use this tractor much and am thinking that I could just go back to the original 3 brush and cutout system to lessen the complexity of its charging system. This tractor does have lights but I nearly never operate at dark.
What am I missing? Thanks

You indicate the generator motors correctly (Faster with the field wire off, and slows with the field wire grounded) this is an indication of complete circuits within the generator, thus it will operate. The questionable components may be the wires or connections. The light switch should be completely out of the circuit. the first two positions should be considered "lights off", nothing to do with a voltage regulator equipped generator. Your first step is to determine if your regulator is a true regulator, and not just a cutout. Cutout relays of that era often have a terminal labeled F. it is used only for a tractor with no lights and is just (internally) a resistor to ground that is the same as the L resistance of the light switch. The real voltage regulator has two relays under the cover. One is the cutout, the other is voltage control. (see image below)
So, if you have the light switch hooked to the F terminal it should not be! Assuming it is a real VR, make sure it is absolutely grounded to the generator directly, or through the block if not mounted on the generator. Jim

 

[43ford]

Thanks for the diagram. I took the light circuit completely off and wired the generator, two coil regulator,and amp meter as per the diagram.
Got some success!
The amp meter is now showing a positive charge. Albeit only about 3 amps. And when I full fleld the field terminal to ground I see 7 to 8 amps.
Generator output voltage at 3/4 throttle seems somewhat low. Only about 6.35 volts.
Can I adjust the voltage control contacts to increase the voltage output? If so how can that be done?
I do have the movable 3 brush closest to to A terminal brush on the generator.
Thanks for your help.

 

[Janicholson]

Thanks for the diagram. I took the light circuit completely off and wired the generator, two coil regulator,and amp meter as per the diagram.
Got some success!
The amp meter is now showing a positive charge. Albeit only about 3 amps. And when I full fleld the field terminal to ground I see 7 to 8 amps.
Generator output voltage at 3/4 throttle seems somewhat low. Only about 6.35 volts.
Can I adjust the voltage control contacts to increase the voltage output? If so how can that be done?
I do have the movable 3 brush closest to to A terminal brush on the generator.
Thanks for your help.

The Voltage relay is the one with smaller contacts. There is a spring that links to the movable contact (there are differences between manufacturers that prevent me from being specific) this spring controls the force applied to the contacts keeping them closed. the first step is to look at the contacts to make sure they are conducting (little or no resistance between them) when the F terminal is disconnected. If there is I would use 400 grit paper to polish them so they actually do make contact. That might just do the trick as is. If charging voltage is still low (should be 7 to 7.2 volts at 3/4 throttle) tweaking the spring to apply more closing pressure is next. (incremental, not big changes. The cover on the VR needs to be in place to accurately assess output as it changes the magnetic forces in the two relays. Jim

 

[gene bender]

I have an A that has not been charging the battery. I have a three brush generator that motor tests ok.
The regulator is a two coil type and I have a three position switch. The switch works fine for dim and bright lights.
I have traced all of the charging wires which seem correctly connected.
I am not seeing any movement at the amp gauge when the engine is running except when the lights are turned on. ( amp gauge shows discharge).
I tried connecting the generator field terminal to a good ground and still had no charge indicating at the amp gauge and the battery voltage did not increase.
Do I have the correct components? Three brush generator and two coil regulator ?
All wiring terminals have been cleaned and soldered.
I appreciate any and all suggestions.

First thing you need a 4 position sw for that gen which gen so you have the 1101435 gen and is that regulator made foir that gen or the the 1101355 the reg must match the gen