Calling all charging system gurus!!!!
 

I've got a quick couple of questions for you.

I'm working on my Original's charging system. It's VERY basic, with only about 5-6 wires! :bigeyes:

I bought the tractor a couple of weeks ago so I have no background on the tractor at all. I started checking the system and the S/G would start the engine, but it wouldn't charge. I suspected the wiring was at least part of the problem. I was right.

I checked the system per R. Bedell's excellent schematic and some of the wires were not hooked up. Now, with everything where it should be, the S/G is constantly charging at 16.5v-17v when I rev the engine up. The Field terminal on the regulator is constantly grounded. I'm thinking that the regulator ISN'T regulating.

I know that there are contacts inside the regulator and I'm wondering if maybe one of the contacts is stuck closed, thereby constantly grounding the field terminal? It is grounded right at the regulator.

I have another regulator from another tractor, but the soft-metal wire (wraps around two poles inside the regulator and acts like a fuse, I believe) is burned. If this soft metal wire (fuse) is replaceable, I would swap out the regulators and see if that helps. If it's not, I'll have to get another one, or figure out how to fix the one currently on the tractor.

If I remember correctly, there is also a way to adjust those regulators. Anyone know?

I put in a new battery and I'd hate to smoke it due to over-charging.

Any insights would be greatly appreciated. Thanks!

No hassle at all...

I did a little 'vestigatin' and noted the adjustment screw on the spring of the magnetic coil that grounds the fields pole on the S/G. I screwed it out to where the points were not touching (no spring pressure) and then fired up the tractor. I slowly screwed it in with the revs up until I saw 13.7-14v on the digital meter.

I'll be checking it on occasion to make sure that is exactly where it should be. On the other side of the coin, I learned a little bit more about my Cub today!

:beerchug:

That is not a fuse, it is a wire wound resistor! Regulators have no fuses inside/outside. Ya you can adjust a regulator, BUT not recommended as they are set @ the factory in a temp/humidity controlled environment. That said, I have back in my young days in the '50's adjusted them because of lack of funds, and sometimes you get lucky if you don't move them much. Some regs back in the day, did have an external adjustment screw/knob that was marked more/less charge.

Ol' George,

not talking about the resistor under the regulator, there's a "wire" inside that I was speaking of. I'll take a photo of it today.

vr
 

Hi C5, Good job adj that v/r, hope it keeps working. I/ve looked in a lot of v/r. Those wires inside you speak of, some i've seen are thick and some are hair like thin. Must be for different current carrying ? A lot of them are marked inside, 13.?, 14.? 7.?. I have some off 6 volt fords. Good luck Mike

Here's a picture of that wire. It's just wrapped around the posts at each end. It reminds me a lot of a fusable link-type of wire. I have good reason to believe that this regulator is good, save for this one wire that is burned through. I'm sure that it has a specific value for the right amount of protection so I don't want to "put a gum wrapper around it" so to speak. :biggrin2:

The newly adjusted regulator is working fine. Hopefully, continues to do so. But, if it should ever decide to take a dump, I'll hopefully have this one ready as its replacement.

C5,

The wire you call out on your regulator is just plain old solid 18- 22AWG hookup wire. As was mentioned ealrier, there are no "protective" devices or fuseable links inside the regulator (but fusing the SG really isn't such a bad idea.)

Here is another view of the same regulator.


http://i1228.photobucket.com/albums/...ps113fd888.jpg

The wire connecting the relay to the terminal is probably to support field current (I'll have to check and get back to you). In either case, field current or relay voltage sense function, #18 - #22 AWG wire should be fine.

The relay to the left is the current sense relay. Note the much larger physical size of the wiring wrapped on this relay. The current limit relay activates from the magnetic force developed by a few wraps of larger gauge wire carrying up to 15 amps of current .

The voltage control relay consists of hundreds of wraps of smaller gauge wire whose function is to respond to the voltage present across its contacts.

Either relay, when activated, can remove the ground from the field of the generator - shutting down power production. In order to keep the generator from slamming full on to full off, a power resistor or resistor(s) in some setups (shown below)


http://i1228.photobucket.com/albums/...rtscallout.jpg


allow a minimal amount of field current to flow even when the regulator cuts off the ground to the generator. With the power resistors functioning properly, the generator is either full on or "somewhat" on - never fully off.



.

Thank you for the info Save_old_iron!

That was VERY helpful and informative.

Went back and checked...
 

I had a bearing that was simply SCREAMIN' at me to change it. So, I did.

When I put it back together yesterday, I had a nice, clean 13.8-14v at the battery when charging (rev'd up). I checked it today, and NADA!

I have 12.4v at the battery at all times. When I check it at the "A" terminal, I only get about .8v. When I ground out the "F" terminal, I get around 1.6-2v at the "A" terminal.

I bench-tested the S/G, and have 8 ohms between the "A" and "F" terminals. I checked the brushes and they are making good contact. Wires inside look to be solid, with no abrasions or breaks. The fact that the "F" terminal does make a difference makes me think that the field side IS working. The tractor does start fine, just doesn't charge. Grounding the "F" terminal bypasses the regulator, correct? So, THAT shouldn't be an issue.

I DID have a good charge yesterday. The fact that I was inside the generator/starter to replace the bearing would make me suspect that my fat fingers most likely had something to do with it, but it DID work after I removed my fat fingers! :BangPC:

Could a field coil have a short/open? I cleaned out the housing/armature so, could carbon have something to do with it.

Any thoughts?

Sincerely,
Chargeless in Florida...
:biggrin2:

In order for the charging circuit to work, you have to have a good ground. With a VOM or DVM, you should have and see, zero (or near zero) ohms from the S/G Mount to the GRD terminal on the V/R.

BTW....the S/G puts out about 15 Amps worth of power. It would need a minimum of 14GA wire for proper conduction.

Thought I HAD it!
 

But, I didn't...

I went back and looked at the ground(s) at both the V/R and the S/G. I figured that since I repainted the S/G (it was off and available) that perhaps, the new coating covered the path of current to ground. So, I cleaned the mount for the ground cable (bolt at the rear S/G mount) and while looking at the V/R, I noted that the small ground strap was very brittle. So, I re-soldered a new on on and installed a star washer to help it bite into the metal at the mount.

Then, I took a reading after hooking the battery back up and engine running. Nuthin.

I've heard that it isn't necessary on S/Gs, but i decided that since I had the battery disconnected and removed the S/G, I'd polarize the S/G. After doing that, I started the engine and the DVM showed 14-ish volts! VOILA! It was now working! :beer2:

Then, I idled it down to check the voltage and when I ran it back up --- Nuthin' :bash2:

i shut it off, and sometimes when I'd re-start, it showed 13.5-14v, and other times... nuthin.

Even grounding the field terminal only shows 1.5-1.8v at the "A" terminal. My brother said that "it may be charged and may not NEED that much current." but I'm thinking that grounding the "F" terminal would still make it charge fully, regardless of battery level, right?

R. Bedell,
Grounding the "F" terminal directly to the battery would also negate the ground path between the V/R and generator also, right?

In the middle of learning a LOT about these little tractors and their charging systems. :BB&YS:

Thanks for the insights!

Work it!
 

I'm certainly as attentive to the experts as C5Rider, because I like to understand how things work, and I've learned much from the explanations thus far. However, one could take the "practical approach" and run the tractor over a period of time in order to see if the charging system is working "well enough" to get by, and perhaps, as your brother contends, it is working as designed. :)

Sounds..............like an intermittent wire connection somewhere. Start the tractor and hook up and volt meter across the battery terminals. Start wiggling charging circuit wires and watch the meter. You might find the connection that is bad.

Grounding the "F" terminal will cause the SG to output full power irregardless of the battery state of charge. You should see at LEAST 15 - 16 volts from the "A" terminal with the field terminal grounded and engine running 3/4 throttle or above. Maybe a cold solder joint on the F terminal stud inside the SG motor? Flashing the field may have temporarily healed a cold solder joint in the field circuit and allowed the SG to temporarily come back to life. The field coil resistance measurement you made with an ohmmeter will not stress the integrity of the cold solder joint like actual operating current will. The ohmmeter only puts microamps of current thru the F terminal connection vs 2 - 3 amps when you ground the field.

I agree with Roland, sounds like an intermittent connection somewhere. Both the ground wires AND the battery (+) connection to the gen and battery need to be in good condition.

@ Rowland - If you mean 14 AWG should be used inside the regulator unit, the wiring I refer to inside the unit only carries the current to the FIELD coil - the wiring can be substantially less than 14 AWG to carry the 1 - 3 amps of field coil current.
http://i1228.photobucket.com/albums/...y/676fe03e.gif

Definitely learning a lot from this process, and hopefullly others who might have this problem (and stumble upon this thread) might also learn, and solve their charging issue as well. Thanks for helping that happen!

I was of the mindset as Save_old_iron and when I grounded the field coil, as that eliminated most (if not all) of the wiring harness. Therefore, an intermittent wiring fault would pretty much be limited to the wire leading from the generator to the (-) side of the battery or inside the generator.

I'll start with the ground cable and work my way inside.

As they say, film at eleven!

:bigthink:

The wiring to the field, armature, to and thru the tractor chassis, and battery all have to be in good shape for the SG to charge with the field grounded. However, the SG is acting as motor to start the engine. Sooooooo... that leads me to believe the main battery cables to the chassis and to the SG are good.

I'm betting my lunch money on something internal to the SG. As you said - we will see later on today.


Chuck

Had a chance to spend a little bit of time on it over lunch.

I can't say that I fixed anything, but I did look around inside. I checked all the wires to be sure that they weren't rubbing the case, and i checked the coils that they weren't an open circuit.

I do have one question though. I hooked up my test light to the "F" terminal and when I touched the (-) battery terminal, nothing happened. BUT, when I touched the (+) terminal, the light lit up.

Does this show that the field coil(s) are shorted? Would that allow that they would not produce current? They did this with the engine running and with the key off.

Thoughts?

Well, it's working fine now
 

I had a little bit of sunlight after work and decided to bite the bullet. I went out and decided to swap out the wiring.

I followed R. Bedell's wiring schematic for the Original and installed the other voltage regulator (almost new) that came off of my other original. There were a few things that I wanted to clean up about the way the previous owner had things wired, I was just hoping to wait until I tore the tractor apart to make those full-on changes.

I decided to make them now and remove the old, scraggly-looking wiring in hopes that the issue I was having would go with them. I ran 8-gauge for the starter button and battery (+) and (-) and 12-gauge for the rest of the system.

i don't know if it would have helped or not, but I checked the system with a digital multi-meter before hooking up the battery terminal solidly. I hooked up one terminal and then put the DMM between the other terminal and the battery wire. My thought was if there was a short, this would show as current without the solid connection (and possibly smoke something). Like I said, not sure if it would have helped but...

I didn't have any problems so I hooked up the battery. I fired up the engine and it was charging fine. I was happy!

Then I shut it off. And it didn't! :bigeyes:

It kept idling (chug, chug, chug... )

I thought that was wierd. I turned the key back on and it chug, chug, chugged a little quicker...

Turn it off, and it chug, chug, chug...

So, I pulled the spark plug wire...

Chug, Chug, Chug.. :bigeyes::bigeyes:

Then I thought: It's feeding the starter! So, I pulled the (-) battery terminal and that shut it off. Had me going for a minute. :biggrin2:

I unhooked the armature terminal from the S/G and tapped the wire to the battery terminal to see if I could hear the relays in the V/R making and breaking. After a few taps, they quit clicking. I tested them a few times afterward and couldn't get them to stick again. This was with the key off.

I turned the key on and things worked as normal. I checked it a few more times and they worked when they should, and didn't when they shouldn't. Plus, it was charging! :beerchug:

Had my head scratching for a few minutes there!

Thanks for the help, and the moral support.

Ah yes - say hello to your newest friend, the CUTOUT RELAY in the regulator.

The cutout relay contacts are normally open until the engine is running fast enough to run the SG at a speed which allows the SG to switch over from being a "starter" to becoming a "generator".

When the engine / SG running fast enough for the SG to generate approximately 10 volts or more output,
the CUTOUT relay windings are energized by the SG's 10 volt + output and the contacts of the cutout relay then CLOSE - allowing the SG generator power to flow thru the regulator to the battery.

Think of the cutout relay contacts as an electrical bridge between the battery and the generator.
Backing up half a step, when the SG is used as a starter, engine speed is low so the cutout relay is NOT energized and the bridge between the battery and SG is open. This is normal.

So let's say the engine doesn't start and you shut off the ignition switch. NORMALLY the cutout relay contacts are open (remember no SG output = cutout relay contacts open). If the cutout relay contacts are open (as they should be), there is no electrical connection between the battery and the SG at this time. Follow the black arrows below - the SG is disconnected from the battery by the open circuit at the cutout relay contacts).


http://i880.photobucket.com/albums/a...ps2e0314ba.gif


Now let's say the cutout relay contacts are pitted and they happen to stick together (not normal operation). There is now an electrical bridge between the battery and the SG and the connection remains intact even tho the ignition switch is off - battery power is now back-fed to the SG and allows the SG to become a starter again. Chug Chug Chug.

You are lucky the tractor was not in gear. I have seen tractors parked in sheds in gear walk out of the sheds by themselves if the cutout relay sticks.

And BTW, if you start messing with the regulator and accidentally close the cutout relay contacts with your fingers, the tractor will start to crank - and you won't be able to stop it until you open up one of the battery cables or physically separate the cutout relay contacts. Why? Because when you close the cutout relay contacts by mistake and the sg becomes a starter, current thru the cutout relay windings is now high enough to energize the cutout relay and keep the contacts closed !!

Both of these are hard to do if you left your tractor in gear and you are now chasing it across your lawn into your neighbor's yard !!

Another point while we are discussing this - the "back- feed" path thru the cutout relay was not meant to handle the load of the SG starter current. Backfeeding the SG in this manner is harmful to the relay coils in the regulator unit. Extended "back feed" cranking can overheat and destroy the coil windings in the relays in the regulator unit. The starter current was meant to be bypassed around the regulator and handled thru the starter relay wiring (in green below).


http://i880.photobucket.com/albums/a...d_iron/vr2.gif


and that is all your going to get at 3 in the morning. Let me know if you have questions.

Excellent explanation Save! That helps explain why there isn't any current flowing through the blue wire in R. Bedell's wiring diagram (which I'll include in this post, but can't take credit for) with simply the key on.

I knew that the starter button prevented any current from flowing through the heavy red wire to the S/G (if it's working properly) and wondered how the blue wire was energized, if it didin't have any current with the key on, engine running.

This helps me understand why (at 6am). :biggrin2:

Thank you!

As soon as the neighbors are up, I'm heading back out there to make sure that it hasn't forgotten how to charge! :popcorn:

and don't linger too long on making VOLTAGE measurements on the field terminal - try to limit your thinking about fields to grounded = generator on, not grounded = generator off. If you could vary the VOLTAGE on the field coils you could vary the power produced at the output of the SG and wouldn't need the regulator clattering away with relays to do it. I do believe there are electronic circuits available which you can place into a gutted regulator case and create an electronic voltage regulator.

In regards to some of your earlier posts, the field coils do not generate power, they ENERGIZE the field shoes to become magnets - magnets of a DC motor (the SG). There are no permanent magnets in the SG so the field current needs to be present to create ELECTROMAGNETS out of the field shoes. When field current flows and the field shoes become magnets, the windings in the rotating armature are swept thru the magnetic fields and current is induced in the armature windings - which then heads out the "A" terminal to charge the battery.

I smell pancakes on the griddle - I'm outta here ............

Thanks for the clarification. As is the case most of the time, I know enough to be dangerous, or get the job done. Problem is, knowing which is which before the mushroom cloud appears! :bigeyes:

To clarify further, the shoes are actually the metal plates that the wire wraps around on the coils, correct?

BTW: went out and checked, still charging like it should!

So I understand this correctly, you are working on the Original Model....and not the 129...???

Yes they are sometimes called pole shoes.
And back when we went to Alternators in the early 60's on vehicles, they had a Regulator that looked like a voltage regular "box" but with a shorter cover, it was Electronic inside,no points to burn/vibrate.
Motorcraft (Ford) made them to replace the earlier V/R equipped vehicles that had Generators, Think I still have one around here someplace.
They were in a "kit" with a short adaptor harness.
Kind of an "upgrade" and it worked well.
Always wanted to figger out how to adapt that principal to these old S/G systems,
but I gave up,and on the bigger tractors, I just put a $5.00 junk yard alternator on them. quick,simple and trouble free.

Roland helped me with the same issue with my tractor..... Filing the burrs off the relay contacts fixed it.

That is correct. Probably have me mistaken for someone else. I've only got two "O"s and a 1715 (mower).

Wouldn't MIND a 129, and a 1250, and a Lo-Boy...

You get the idea. :biggrin2:

I'm gathering that there is a LOT of information that can be gleaned on this subject. The current "use and discard" mentality of today has really limited the knowledge base of many items today.

Would be good for folk to know HOW to rebuild/repair many items, even if they choose not to.