Genny Discharging on Cub (tried almost everything) - John T

I got this little Cub, and its a really nice tractor. It runs Really Excellent, and it appears that someone really took their time "re-doing " it a few years ago. I bought it from a guy that was deceased so I can't verify anything. It is all complete and original, and when I bought it, it was running good (minus a dirty carb that would only run at half choke, and a bad battery). After closer inspection, the steering box was rebuilt, the transmission possibly rebuilt because its super quiet, and the wiring wasn't original but was done nicely and all ends were heat shrinked at the time of re-do. Since it didn't have any leaks and had splotchy and faded paint; I decided to re-paint it. We also went ahead and bought a new battery, and put a freshly rebuilt carburetor on it. The other carb was a Carter with an oversized flange, and I put the original IH back on it).

I noticed after replacing the battery (6 volt system, but went with 8 volt since its all the store had), is that the generator is showing that its Discharging. All of the connections are good and tight, and I cleaned the ones on the regulator with battery cleaner and wire brushed them because they were corroded. I also changed one that was corroded at the wire. I troubleshooted the wires at the regulator to see if I had a "spark" when disconnecting.....I had one at the "GEN" terminal on regulator at first, but noticed that the right spring under the regulator cover had popped off. After putting spring back on and bending the top spring tab upward a little so it would stay on, it doesn't spark there anymore. I tried all the other connections on the regulator for that "spark", and didn't have one on any of the other terminals. I also went ahead and polarized the generator, still no change. All of the wiring at the generator and voltage regulator is coerrect, and everything works as it should (minus the gauge showing discharge), so I bet the wiring is correct behind the dash. The lights, kill switch, and fuse for lights is all hooked up correctly. Also checked the battery cables at battery, no spark and no movement of ammeter when I disconnect and reconnect cables.

What can be the problem??

Forgot to mention, that I have followed your troubleshooting guide too.

Would you believe a 6 volt generator can not charge a 8 volt battery. At best you will have a battery that has maybe 7 volts in it. Of course you also may have a generator that is just plan and simple bad and needs to be rebuilt

Are you sure you hooked the batt to positive ground then polarize the gen. Playing with regs can sometimes do more harm than good.

It is hooked to positave ground, nice and tight and clean and bright.

I simply put the spring back on the regulator. When the spring came off, the ammeter went to about 10-11 amps on the discharge side. Normally, it is around 4-5 amps discharge. Once I fixed the spring back, it returned to the 4-5 amps discharge.

Hmmmmmmmmmmmmm, this may take some doing.

Okay, your language sounds like you have a full fledged Voltage Regulator (3 or 4 terminals, BAT GEN/ARM FLD LOAD if its a 4) instead of a simple Cutout Relay (usually 2 sometimes 3 terminals, BAT and GEN/ARM).

Heres the deal, ifffffffffff its just a simple Cutout Relay, a 6 volt genny can charge an 8 volt battery, although not at any high charge rate. HOWEVER if its a Voltage Regulator which utilizes a voltage control relay, its not gonna charge an 8 volt battery well (if at all) until its adjusted and thats tricky to describe over the net, Jim N has helped with that before I believe.

OKAY, if its a 4 terminal VR many of those have the ARM/GEN terminal underneath or off on one side by itself while BAT FLD LOAD are together, SURE ITS WIRED RIGHT????????????

OKAY, Regardles if a VR or relay, IT (the relay or VR plus genny itself of course) MUST HAVE A GOOD GROUND TO WORK, be sure its case is well grounded, try a jumper wire maybe to check it out.

OKAY, regardless what it has, when shes running try to momentarily dead ground the gennys FLD post n see if she charges then???? If so but not otherwise, the genny itself is okay so theres a problem in the VR (or its needs adjusted) orrrrrrrrrr the VR isnt well grounded,,,,,,,,,or the wires bad from FLD on Genny to FLD on VR or up to the light switch (if its a cutout relay system) ,,,,,,,,,,or the light switch is bad or not well grounded (again if its a cutout system)

If its a VR and you use an 8 volt battery it may work if adjusted but if a cutout relay it can work (maybe not high amp rate) with nothing done ifffffffff all else is okay

Insure correct wiring (if its a VR),,,,,,,,insure VR or relay has a good ground,,,,,,,,try to dead ground the gennys FLD post when shes running at high RPM and if she then charges the genny is okay so a VR must need adjusted or isnt well grounded or if its a relay system the LHBD switch is bad or not well grounded or teh wire from FLD on genny up to switch is bad.

Does the genny pass BOTH my Motor tests??? maybe the genny is just bad????

Thats enough for now

John T

(quoted from post at 23:46:56 09/04/11) Hmmmmmmmmmmmmm, this may take some doing.

Okay, your language sounds like you have a full fledged Voltage Regulator (3 or 4 terminals, BAT GEN/ARM FLD LOAD if its a 4) instead of a simple Cutout Relay (usually 2 sometimes 3 terminals, BAT and GEN/ARM).

Heres the deal, ifffffffffff its just a simple Cutout Relay, a 6 volt genny can charge an 8 volt battery, although not at any high charge rate. HOWEVER if its a Voltage Regulator which utilizes a voltage control relay, its not gonna charge an 8 volt battery well (if at all) until its adjusted and thats tricky to describe over the net, Jim N has helped with that before I believe.

OKAY, if its a 4 terminal VR many of those have the ARM/GEN terminal underneath or off on one side by itself while BAT FLD LOAD are together, SURE ITS WIRED RIGHT????????????

OKAY, Regardles if a VR or relay, IT (the relay or VR plus genny itself of course) MUST HAVE A GOOD GROUND TO WORK, be sure its case is well grounded, try a jumper wire maybe to check it out.

OKAY, regardless what it has, when shes running try to momentarily dead ground the gennys FLD post n see if she charges then???? If so but not otherwise, the genny itself is okay so theres a problem in the VR (or its needs adjusted) orrrrrrrrrr the VR isnt well grounded,,,,,,,,,or the wires bad from FLD on Genny to FLD on VR or up to the light switch (if its a cutout relay system) ,,,,,,,,,,or the light switch is bad or not well grounded (again if its a cutout system)

If its a VR and you use an 8 volt battery it may work if adjusted but if a cutout relay it can work (maybe not high amp rate) with nothing done ifffffffff all else is okay

Insure correct wiring (if its a VR),,,,,,,,insure VR or relay has a good ground,,,,,,,,try to dead ground the gennys FLD post when shes running at high RPM and if she then charges the genny is okay so a VR must need adjusted or isnt well grounded or if its a relay system the LHBD switch is bad or not well grounded or teh wire from FLD on genny up to switch is bad.

Does the genny pass BOTH my Motor tests??? maybe the genny is just bad????

Thats enough for now

John T

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WHEW!!!! Thanks so much John T. Its gonna take me a while to try and decipher what was just said, and what to do now. Haha, but from your last paragraph I am going to go out and make a diagram of the wirring and snap some pictures so we can all see what I have. I will also try to dead ground the FLD wire on the generator. Do I simply unhook it and ground it to the case/frame, or a jumper wire to ground on battery? I didn't try the motor tests, but let me get this stuff checked out and pictures taken, and we'll go from there. Thanks again!!

Ok, here is what I found out. I traced all of the wires back and drew a rough sketch of the way the tractor is wired. It looks correct to me with the exception of a couple of things near the light switch and fuse that I do differently. I don't think that would have an affect on the genny though. Looks like I have the voltage regulator since it has the 3 terminals in the rear and 1 in the front. Another sign is that the light switch is the standard 3 position type without the resistor at the bottom.

Dear RTR,
If you have two individual coils of wire and contacts inside the Device we will call a Voltage Regulator (VR) it is a VR. If it has only one, it is a cutout relay.
Assuming a VR, (which consiste of a cutout relay and a voltage regulating relay in one tin box)the spring you replaced is probably on the cutout relay. This spring is designed to prevent the contacts associated with it from closing if the gen is not charging above battery volts. It connects the Gen armature with the Battery through the amp meter. If it is closed when the gen is not turning, or turning too slowly to make enough voltage to charge the battery, the battery will discharge into the gen, depleating the battery rapidly. When the gen is turning rapidly enough (1/2 throttle or more) the gen voltage exceeds the bat voltage and the battery will be charged.
When the gen then slows down (or stops) the gen will be producing insufficient voltage, and the cutout will sense the reversed current flow and open, preventing battery drain.
The Voltage regulation relay contacts are not connected to the cutout at all!! They have a common ground with the VR frame, but nothing else. The voltage relay coils are connected to the cutout to get charging voltage.
The Voltage relay controls the grounding of the field coils in the gen. The more direct the ground the more voltage is produced. when it is stopped, the ground is direct. When it is running fast enough to charge, the voltage applied to its coil will vibrate the points open and closed like a buzzer to limit the average voltage to the preset battery voltage. In the case of your VR, it is 7.2 (or close to that) volts.
What to do!
I would not use the 8 volt battery. it is way not needed on a Cub. A 6 volt will allow the charging system to function as designed, and not require modifying the VR voltage relay to make more volts.
I would also believe that the spring you had come off, and bent the tab to replace has dramatically changed the settings of the cutout.
This can be adjusted with the tab on that spring. It should allow the gen (with a fully charged 6v battery) running at 3/4 throttle. To pull the contacts closed at a voltage of about 6.5. and open the contacts when the gen voltage drops to about 6.2 or very close.
If the tractor is idled down to lowest speed, the amp meter should momentarily drop below 5 amps discharge, then flip back to 2 to 3 amps discharge. (lights off)
when the RPM is increased, the Amp gauge will suddenly jump to charge.
THis is a tickelish adjustment, with tweaking required, and few experts left in the trade to do it correctly. A very good Auto electric company can set it up if they have the battery, Regulator, and Gen. (or the whole tractor)
The cover must be on the VR when the testing is being done as the cover changes the magnetism and must be accounted for when assuming it is correct.
Purchasing a new VR and 6 v battery might be a least hair pulling situation.
Jim

Cutout on left, VR relay on right (2nd and 3rd pic down). See above! Jim

Jim, are you saying that you think the generator is ok and putting out. Like you said, it seems like it is not "Jumping" to the charge when it is revved because it shows a discharge of about 4-5 amps (maybe 3 amps). It shows that constantly, regardless of engine speed. Are their any other Tests I can preform to verify that the Voltage Regulator is the culprit. THANKS!

If you open the regulator, Leave all wires connected, short the field terminal to ground with a jumper (at the VR or Gen either one), start the tractor and run it at 3/4 throttle, and jump from the Arm terminal to the Bat terminal with a piece of 10 gauge insulated solid wire with 1/4" stripped from the ends, it should charge, A 6v generator into an 8 volt battery won't charge more than about 6 amps (probably). Do not leave the jumper on the Arm to Bat terminal when idleing or shut off, things could smoke! Jim

Jim,

If its ok, I will just unhook the Feild Wire from the generator and hold it to the case/frame to ground it. Then I will use a 8 inch peice of 10 ga wire with 1/2 inch stripped off each end to jump.

I did this before, but did it with the tractor not running, but battery hooked up. I got a spark when doing it, which I thought was good.

Let me go and try it while its running at 3/4 throttle.

The wire can be hooked up when doing this. And!!!! the thing that needs grounding is the field post on the gen, not the reg!! Jim

(quoted from post at 03:22:42 09/05/11) The wire can be hooked up when doing this. And!!!! the thing that needs grounding is the field post on the gen, not the reg!! Jim

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I took off the Feild wire (one closest to me) on the GEN. I grounded it to the engine of the tractor. Started the tractor and ran it at 3/4 throttle. Then I used a jumper wire and touched the BAT and the FEILD terminals on the Regulator. No change, and no spark. I think I will need to try once more when I have a helper to hold the ground wire better. I will try tomorrow again. If I am doing it wrong (or right), please let me know! THANKS!

Okay, from your pictures and diagram you have a Voltage Regulator so heres how to see if non charging is the fault of the Genny or the VR.

DONT FORGET THE VR NEEDS A GOOD GROUND

DONT FORGET TO PROPERLY CHARGE AN 8 VOLT BATTERY THE VR (if it has a voltage control relay) NEEDS ADJUSTED

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. YOU DONT HAVE TO UNHOOK THE WIRE FROM THE GENNYS FLD TO THE VR, YOU CAN JUST JUMP THE GENNYS FLD TO CASE FRAME GROUND


6. If she still don’t charge, leave the Field grounded and jump a wire across from the VR's BAT terminal over to its GEN terminal or direct to the Gennys ARM post (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 not wired correct.

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


John T

Thanks so much John. I will check it tomorrow. Even though it is an 8 volt battery right now, it should still at least charge some like it would a 6 volt. That is all I need for now because I just want to figure out what the problem is, so I can get the hood back on.

The field terminal on the gen needs to be jumped to ground (any time is OK stopped or running) wire to VR hooked up or not. If the field is grounded the generator will make output if it can. With the wire disconnected (as in your description of what you were going out to do) will not charge. Jim

He tried the jumping routine, but grounded the field wire from the VR when it was disconnected from the gen. Thus nothing.
I explained it in the post I just placed.
He also tweaked the spring on the Cutout. Thus my suggestion. In the responses he and I have been making. This is fun! Jim

Haha, this is fun Jim. I just want to figure out what the issue is. I sure am learning alot about Generators and Voltage Regulators, and Cutouts.!!!!

I will try your suggestions tomorrow and leave the Feild wire hooked up. I have a jumper wire with alligator clips to use.

THANKS!!

Ok guys, here's an update.....

I went out and started the tractor up and ran at 3/4 throttle. With everything hooked up (no wires removed), I hooked a jumper wire with alligator clips to the FEILD terminal on the generator, and the other end to the upper generator bracket for a ground. When I did the ammeter jumped up to around 10-11 on the charging (+) side. We thought maybe it was a ground issue. I unhooked the left screw that holds the regulator on, and scratched the surface well with a screwdriver and replaced it. Still no change. It charges only with jumper wire. Then I decided to replace the regulator with a brand new one I had on hand. After replacing the regulator, stil lthe same thing. It only charges with the jumper wire.

Any thoughts??????

The new voltage regulator will not charge an 8volt battery. It is set for 7.2 or so. When it sees an 8.4 volt source (charged 8 volt), it realizes it has no business charging. To make it work, it will be necessary to adjust the voltage relay spring so it is tighter, this holds the contacts together harder, making more voltage.
Doing this also runs all parts of the electrical system at ablut 9 volts. It is hard on the points and coil. it burns lights brighter, but shortens their life to about 1/2 normal or so.
It also rund more current through the field coils heating the gen more than normal.
None of these things are forbiden, but that little cub needs a 6 volt battery. You now know it can charge, (gen good) and with a 6v it will do so as is. Jim

Jim,

I understand that it will do that once I use a 6 volt battery; however, it is doing the same thing it did with the old regulator on....show a discharge until I jump the Generators FEILD post to a ground source, in my case is the upper generator bracket.

Once you jump it with the jumper wire, it moves the ammeter up to the charge side and reads around the 10 mark. That is what I am wanting it to do WITHOUT the jumper wire. I also looked down inside the Generator (dust cover removed), and you can visually see it genning.

The regulator sees 8 volts it is set for 7.2 it will not charge unless modified, and it is touchy to do. It does not compute 2 volts over battery volts it is not smart!. Jim

(quoted from post at 17:45:18 09/06/11) The regulator sees 8 volts it is set for 7.2 it will not charge unless modified, and it is touchy to do. It does not compute 2 volts over battery volts it is not smart!. Jim

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So..is that why it all of a sudden starts charging when I use the jumper wire??...beacuse I am bypassing the regulator which is confused by the 8 volt battery. (read my last 2 posts)

Well now you know it will charge when you ground the F terminal to the case. Try grounding the Field terminal at the regulator instead. That will verify that the wire and connections are good.

UPDATE!

Ok guys, I went out tonight and replaced that 8 volt battery with a good 6 volt battery. I started it up, and had NO MOVEMENT from the ammeter whatsoever. I decided to use the jumper wire with clips to see what difference it would make. I clipped one end to the Feild terminal on the genny, and the other end clipped to the genny bracket to ground it. I noticed a spark when I clipped the wire to the generator bracket, and looked back at my ammeter, and still no movement. It is just sitting on 0. Maybe I wasn't getting a good ground on the jumper wire. I couldn't "play with it" because my temporary gas tank ran out of fuel. All in all though, I didn't have any movement in the gauge At All!! Something apparently isn't working right still!! Ugghh.....

(quoted from post at 08:18:30 09/11/11) UPDATE!

Ok guys, I went out tonight and replaced that 8 volt battery with a good 6 volt battery. I started it up, and had NO MOVEMENT from the ammeter whatsoever. I decided to use the jumper wire with clips to see what difference it would make. I clipped one end to the Feild terminal on the genny, and the other end clipped to the genny bracket to ground it. I noticed a spark when I clipped the wire to the generator bracket, and looked back at my ammeter, and still no movement. It is just sitting on 0. Maybe I wasn't getting a good ground on the jumper wire. I couldn't "play with it" because my temporary gas tank ran out of fuel. All in all though, I didn't have any movement in the gauge At All!! Something apparently isn't working right still!! Ugghh.....

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Let me go out here and mess with it to see what I can find. Do you think it could be a ground issue now?? Or maybe a corroded/bad wire under the insulation??

UPDATE:

We put the hood back on, and now when the lights are burning the ammeter reads discharge. With no lights, it just remains at 0 in the middle.