I keep looking over John T's notes for Troubleshooting Charging Systems in the hopes of finding the blinding light I need to sink in and solve my problem. No blinding light yet; but a statement/question.

Lots of references to "grounding". Just to be certain regarding these grounding references.....

I see no "ground" wire anywhere on the electrical system. Should I? (On my old Ford tractor the gen and VR are separate and there is a "ground" wire from the gen to the base of the VR.)

As for "grounding" the gen on this cub, I have the metal shining on the gen frame and block area where the gen is mounted. I have the metal shining on the gen frame at the point where the VR mounts to the gen frame. The VR mounting area metal shines.

The mounting area of the "dash" where it bolts to the "frame" shines as well as the metal onto which it is bolted. The metal in and around the hole where the ignition switch and ammeter are mounted shines from my grinding/sanding.

To the best of my knowledge, all metal contacts where "grounding" should occur have been cleaned well to bare metal.

But, there is no wire anywhere which is grounded to the frame - other than the positive battery grounding cable. Am I missing something?

Oops, there "originally" WAS a "grounding wire" from one of the gen mounting bolts to the coil bracket mounting bolt to a bolt on the top plate of the trans housing. I've taken this wire off, put it on, taken it off, etc. and have seen no useful purpose for it - thus it is now off. Why would such a grounding wire have existed? Do I need it?




Thanks.

The grounds you have are correct. There are only chassis grounds on a Farmall.
Does your generator charge the battery if you are running at 1/2 throttle and ground the F generator terminal with a jumper?
If it does, that is a great place to start. If you are on line answer back. Jim

If you replaced a cutout with a VR, the VR might have 4 terminals (the L terminal should power the lights and ignition)
The Bat terminal goes to the load side of the amp gauge.
The Gen terminal goes to the Armature Terminal on the gen.
The F terminal goes only to the F terminal on the gen.
The old wire from the light switch (that went to the F terminal on the Gen) is abandoned and not used at all.
Jim

If you have the mounting areas clean that what we mean when we say good ground. It helps to use a meter.

Most regulators have rubber bushings on the mounting screws to reduce vibration. There should be a metal tab connected to the regulator base & under one screw head to provide the ground. Lots of people miss cleaning that one.
WJ

Thanks for all the very helpful replies.

Later today I shall probably do the one thing I failed to do regarding John T's instructions - check the generator motor myself per his instructions.

Yes, I took the gen off early on and took it to a reputable gen repair shop where I was told that it was working great. Thus, I've focused on everything but the gen. Now I'm thinking that was my big mistake.

I'll complete the gen motor check myself per John's instrs. If it fails, it will go to a different gen repair shop.

Oops, Jim I failed to respond to your question.

No, the gen did not generate any "significant" charge with the field gen terminal grounded. The battery had been drained somewhat at the time and I did read a 0.4 or so volt increase with that test. Hindsight, I should have focused more closely on that.

Have you looked at the brushes/ holders---wires inside the gen? Check that one of the braided brush wires isn't loose in a brush or loose at a connecting screw or Arm or F terminal bolt. The shop could have missed an intermittent when testing. Even the ground brush connections should be looked at.

The term "Ground" or "Grounding" on those old tractors refers to how the tractors iron frame is used as the return current path for current to the batterys grounded post (thats Pos on old 6 volt Farmalls). If the batteries POS is wired to the frame, then if an electrical device (genny or VR etc) is also wired to the iron frame, current can flow to the grounded battery post via the conductive iron frame instead of having to run a seperate wire

The genny must be Grounded to the iron frame via its mounting bolts,,,,,the VR or Cutout Relay must be grounded to the iron frame often via its mount to the genny itself or else on another iron component.

In your many postings lately you use the terms cutout relay and you also talk about a device having BAT ARM/GEN and FLD terminals which sounds like it may be a full fledged Voltage Regulator?????????????? If its a Voltage Regulator its BAT wires to load side of ammeter (and that wire MUST have hot voltage all the time if its wired correct),,,,,,,,,,,,,,GEN/ARM on VR wires to Gennys FLD post,,,,,,,,,,,,FLD on VR wires to gennys FLD post,,,,,,,,the VR MUST BE GROUNDED. If its a VR theres no wire from FLD on Genny up to a LHBD light switch

If it has a Cutout Relay,,,,,,,BAT to load side of ammeter,,,,,,,,,,,GEN/ARM to gennys FLD post,,,,,,,,,THE GENNYS FLD WIRES TO A LHBD LIGHT SWITCH NOTTTTTTTTTTT THE CUTOUT RELAY


OKAY ONE MORE TIME

TO DETERMINE IF ITS A GEN OR VR OR CUTOUT RELAY PROBLEM

5. a) VOLTAGE REGULATOR SYSTEM: With the tractor running, temporarily ground the Gens Field post to case. If she charges then but NOT otherwise, the VR may be bad, or a wires missing from VR's Field post to the Field terminal on the VR, or the VR isn’t well grounded.

b) IF IT’S A CUTOUT RELAY SYSTEM and she charges only if you dead ground the Field but NOT otherwise, its either a bad switch or the switch isn’t well grounded or else the wires bad or open from the Gens Field post up to the switch. INSURE THAT GOOD SWITCH GROUND AND WIRING

6. If she still don’t charge, leave the Field grounded and jump a wire across from the VR or Cutout Relays BAT terminal over to its GEN terminal (jump by passes the cutout relay) and see if she charges. If then but not otherwise, a VR's cutout relay isn’t working correct (maybe points burned/carboned) or a Cutout Relays NOT working or not wired correct.

7. With the 2 steps above, you have basically by passed the VR or Cutout relays functions, so if she still don’t charge, you're left with a bad battery or wiring or the Gen itself.

8. MOTOR TEST. You can Motor test the Gen. If its grounded and you remove the belt and apply hot battery voltage direct to its ARM Post and have the Field Post dead grounded to frame, it should motor n run well (Armature n Brushes and Commutator likely okay). Then, if you next remove the Fields ground and it speeds up some, the Fields probably good. If it passes both those tests, it should charge, and if not, it may be a wiring or battery or grounding problem. The hot battery voltage may be taken off the VR's BAT terminal or the starter post or the battery itself for this test.


John T

Dont forget to POLARIZE the genny once back on your tractor and BEFORE starting, the genny shop may have it polarized at the opposite polarity !!!!!!!!!!!! If started at the incorrect gernny polarity it can trash the VR

John T

Yes, I've spoken of cutout relay and VR. Cutout has been replaced with VR.

Motor test suggests gen okay, I guess. With F post dead grounded to frame and hot battery voltage to gen ARM post and belt removed the gen turns -not super fast, but fast enough to burn a hand if one was placed against the pulley. With the F ground removed, it does speed up slightly. No change whether ignition switch on or off.

With belt on pulley and engine running and gen's F post grounded and jumper from VR BAT to VR GEN terminal, she doesn't charge - or if so not significant.

With the gen's F post grounded and no other changes - no charge.

Bat term on VR always reads hot.
Bat on VR wired to ammeter's negative post.
(Cable from battery at starter wired to ammeter's positive post.)
Gen on VR wired to gen's ARM post.
Fld on VR wired to gen's Fld post.

Coil wired to one ignition switch post.
Other ignition switch post wired to ammeter's positive post.

Cub doesn't have light switch, thus no wire from L on VR to anywhere.

VR has 4 posts:
F on side
Bat on side
L on side
Unmarked post underneath VR. I'm told it's Arm or Gen post and am wiring from it as such.

Photo attached for any clues. Belt still off from gen motor test.

See other thread. I'm wondering if the engine is revving up high enough to charge - or for more than a trickle charge.

Welllllllllllllllllllll, I agree the Motor test says the gen is likely okay,,,,,,,sounds like its wired right,,,,,,,,,,,the VR by pass test ought to make her charge ifffffffff the genny is really okay as motor test says,,,,,,,,,iffffffffff its turning fast enough??? and the battery is okay and capable of accepting charge?????????

I wonder if its a 3 brush genny???????? If so when I convert from a cutout relay to a VR if the third brush is adjustable??? I set them for max charge condition.......Maybe its a 3 brush adjustable genny and its set for low charge

PS if the battery is good and fully charged and its a 3 brush genny set for low charge I wouldnt expect it to charge a whole lot, maybe only a few amps. Still a voltmeter on the battery should raise at least something if youre at high RPM and the genny is working

To be safe Polarize the genny and do that especially if its been to a repair shop BEFORE starting

John T