Ammeter not showing charge on 6 volt system

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Clubless
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Zip Code: 27041
Tractors Owned: 1950 Farmall Cub
1948 Farmall Cub
Location: NC, Pilot Mountain

Ammeter not showing charge on 6 volt system

Postby Clubless » Sat Jul 23, 2016 8:57 pm

I’m still trying to figure out why my ammeter does not show charge when engine is running. I’ve read a lot of threads on this subject, but still have not figured it out.
I have a "Hillbilly" gas tank mounted so I can run tractor and have easy access to the electrical system.

Here’s what I have:
1950 Farmall Cub
Working lights
Single pole start/stop switch (Do not have any type of ignition switch)
Starter rod to starter
Original 4 position light switch
Original IH ammeter gauge
6 volt positive ground
J-4 magneto
Generator with saddle mounted 4-terminal regulator
New fully charged 6 volt battery (reads 6.37 on voltmeter)
Digital voltmeter tester

Here’s the wiring diagram I’m using:
http://www.antique-tractor.com/CubFAQ/cubwiringlate.jpg
This diagram shows an ignition switch and fuse connected to the light switch and connected to L terminal on regulator and negative wire to coil.
I do not have an ignition switch. I have no wire connected to L terminal on my regulator. Wire for lights is connected to right terminal of ammeter coming from light switch.

Here’s what is not working:
Ammeter shows discharge with lights on when tractor is running or not running
With lights off, ammeter shows neither charge nor discharge

Here’s what I have done:
I had generator and regulator tested by reputable shop. Both generator and regulator are said to be in working order

Tightened up generator belt

With battery ground disconnected, I cleaned all wire connections thoroughly.
4 connections on VR
2 connections on generator
Starter connections (negative starter wire from battery and wire from starter connection to Left terminal of ammeter
Ammeter connections

Tested continuity of wire connected to starter and to left terminal of ammeter as shown in wiring diagram

Tested continuity of wire connected to BAT terminal of regulator and to right terminal of ammeter as shown in wiring diagram

Connected battery and polarized generator

Started tractor and increased RPM

Looked at ammeter and it is showing neither charge or discharge

Turned on lights, ammeter shows discharge

Checked voltage at battery posts with tractor running, got 6.37 reading

Checked generator output by placing negative lead of voltmeter on the BAT terminal on regulator and positive lead to tractor frame (ground), got reading of 6.37 ( Based on reading other post here, I was expecting output to be in the range of 6.5 – 7.5 volts). Is this the correct way to check generator output?

I've attached a couple of pictures of the generator/regulator and starter/magneto to show wiring. Pictures were taken before I cleaned up connections.

The BAT terminal of regulator (middle terminal) is connected the right terminal of ammeter

The smaller wire coming from the starter is connected to the left terminal of ammeter
The wire from the magneto goes to the single pole start/stop switch.

The light switch photo is a stock photo, but it is the type I have on tractor

Thanks for all the help you guys always provide.

Gary
Pilot Mtn. NC

.
Attachments
generator.jpg
Generator/Regulator
starter.jpg
Starter/Magneto
Light switch.jpg
Light switch
Light switch.jpg (23.15 KiB) Viewed 2680 times
Gas tank.jpg
Hillbilly gas tank

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Glen
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Re: Ammeter not showing charge on 6 volt system

Postby Glen » Sun Jul 24, 2016 1:56 am

Hi,
I can't tell if the system is working or not, by that I mean that it could be working and the regulator is set so low that it is not showing a charge on the ammeter. The regulator may need adjusting so the system charges more.
IH never used a regulator on top of the generator, as far as I know, but it may be the same inside as the IH regulator, that were mounted beside the generator. I don't know without seeing under the reg cover. The reg output is adjustable on the IH style reg. :)

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Re: Ammeter not showing charge on 6 volt system

Postby Puffie40 » Mon Jul 25, 2016 2:24 pm

Try motoring the generator - take the belt off, disconnect the VR, and feed 6v to the field while grounding the armature. If the generator starts spinning, your generator is in good enough shape to produce power.

A 4-position switch used a cutout, not a VR. Those were used in the late 40's Cubs, with the positions being (low charge - high charge - dim lights - bright lights)

Since you have some confusion about the wiring diagram, take a look at this thread:

viewtopic.php?t=20714

tst
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Re: Ammeter not showing charge on 6 volt system

Postby tst » Mon Jul 25, 2016 3:10 pm

this might help,that cub system should have a cut out relay on top of the generator, looks like some one put a voltage regulator on it, the light switch you have is made to control the cutout relay voltage
Attachments
cut out charging.jpg

Clubless
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Location: NC, Pilot Mountain

Re: Ammeter not showing charge on 6 volt system

Postby Clubless » Mon Jul 25, 2016 10:29 pm

Ok...thanks everyone for your input and thoughts.

Right now, I'm not concerned about having working lights so what if I disconnect the 4 position switch and take that out of the equation. What I'm really after is for the generator to charge the battery and the ammeter to show charge reading.

How does the output from the generator get to the battery"? Here is how I think it works. The wire connected from A terminal on generator is connected to GEN terminal on regulator, the generator output passes through the regulator to the BAT terminal on regulator which is connected to the right terminal of the ammeter. Current then passes through (causing gauge to show charge) to the left terminal of ammeter which is connected to the starter switch and current travels back to negative post of battery through the starter cable.

Is this even close to correct? Seems to simple for it to be correct. :D

Look forward to your comments!

Gary
Pilot Mtn. NC

And for what its worth, here are a couple of pictures of VR with cover off.
Attachments
VR_1.jpg
VR_3.jpg
VR_4.jpg

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Glen
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Re: Ammeter not showing charge on 6 volt system

Postby Glen » Tue Jul 26, 2016 1:40 am

Hi,
Thanks for the pics of the reg with the cover off. It looks like an IH reg under the cover, having the 2 coils of wire. When you run the engine, look at the left set of points, left as in your 1st pic above, on top of the wire coil, and see if they close, they should be open when the engine is stopped, and closed when you run the engine. It has to be some above idle speed.
If the points don't close, there is either no power there, or the reg is bad, or it's not hooked up right.
The points on the right coil control the voltage output. The more tension on the little spring on the back side of the wire coil, the more voltage it should put out.
I can't tell in the pics if there is a 4th wire that goes under the reg, and hooks on. :)

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Re: Ammeter not showing charge on 6 volt system

Postby Puffie40 » Tue Jul 26, 2016 9:18 am

Clubless wrote:Ok...thanks everyone for your input and thoughts.

Right now, I'm not concerned about having working lights so what if I disconnect the 4 position switch and take that out of the equation. What I'm really after is for the generator to charge the battery and the ammeter to show charge reading.

How does the output from the generator get to the battery"? Here is how I think it works. The wire connected from A terminal on generator is connected to GEN terminal on regulator, the generator output passes through the regulator to the BAT terminal on regulator which is connected to the right terminal of the ammeter. Current then passes through (causing gauge to show charge) to the left terminal of ammeter which is connected to the starter switch and current travels back to negative post of battery through the starter cable.

Is this even close to correct? Seems to simple for it to be correct. :D

Look forward to your comments!

Gary
Pilot Mtn. NC

And for what its worth, here are a couple of pictures of VR with cover off.

That description sounds about right.

Clean the contacts of both relays and take a closer look at the left relay mentioned by Glen. How that is supposed to work is that relay closes when the generator output reaches 6 volts, connecting it to the battery and preventing the system from draining while the motor is off (a giant diode, really)

Watch the system voltage while holding down that relay.

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Re: Ammeter not showing charge on 6 volt system

Postby birddog » Tue Jul 26, 2016 5:13 pm

Here are a couple links for testing the charging system. One has pics. the other schematics.

http://www.farmallcub.com/phpBB2/viewtopic.php?f=140&t=80347

http://www.farmallcub.com/phpBB2/viewtopic.php?f=140&t=80346

Here is one on regulators and cutouts.

http://www.farmallcub.com/phpBB2/viewtopic.php?f=140&t=80345
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Clubless
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Location: NC, Pilot Mountain

Re: Ammeter not showing charge on 6 volt system

Postby Clubless » Thu Jul 28, 2016 11:36 pm

Yesterday I was talking with the mechanic that has been helping me with the tractor, I asked him to check out the generator/regulator. I showed him the above wiring diagram to refresh his memory on 6 volt systems. After some poking and prodding around the electrical system, he concluded that 6.34 volts was about all you could expect from the generator and 6.34 volts was enough to keep battery charged. Later in the day I stopped by the generator shop that checked out the generator/regulator last fall and asked him how much voltage the generator should put out, his answer was 6.5 - 7 volts. I told him mine was showing 6.34 on my volt-meter, he said that would keep the battery charged. The ammeter works, but not enough generator voltage to make needle move to the right.

So, I'm closing the book on the generator for now and will wait and see if battery stays charged.

Thanks again for everyone's help. It's great to be on this site! :beer:

Gary
Pilot Mtn. NC

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Re: Ammeter not showing charge on 6 volt system

Postby JohnMihevic » Fri Jul 29, 2016 6:18 am

If you have a Volt-Ohm-Meter with a 10 Amp scale, you can remove one wire from the ammeter and connect the VOM in series with your ammeter. The sensitivity of the VOM should be good enough to see if you have any charging current. 2-3 amps would be enough to keep the battery charged, but not supply enough current for lights or anything else.

John M.

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Re: Ammeter not showing charge on 6 volt system

Postby John *.?-!.* cub owner » Fri Jul 29, 2016 12:43 pm

This is the diagram for a cutout, which is the one that was posted above:

Image


And this is the one for a factory installed regulator:

Image


Make sure your wiring matches one or the other especially the ammeter wiring. I worked half an hour on one earlier this summer trying to figure out why it never showed a charge to find that whoever put the regulator on in place of the cutout before he bought it had added the L wire lead, but not removed the original wire going to the light switch. It was charging the battery ok, but it never showed on the ammeter.

Here is a trouble shooting flow chart.

Image

All the above Images compliments of Robert Mehleville (Farmall Bob)
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Re: Ammeter not showing charge on 6 volt system

Postby Puffie40 » Fri Jul 29, 2016 2:45 pm

Clubless wrote:Yesterday I was talking with the mechanic that has been helping me with the tractor, I asked him to check out the generator/regulator. I showed him the above wiring diagram to refresh his memory on 6 volt systems. After some poking and prodding around the electrical system, he concluded that 6.34 volts was about all you could expect from the generator and 6.34 volts was enough to keep battery charged. Later in the day I stopped by the generator shop that checked out the generator/regulator last fall and asked him how much voltage the generator should put out, his answer was 6.5 - 7 volts. I told him mine was showing 6.34 on my volt-meter, he said that would keep the battery charged. The ammeter works, but not enough generator voltage to make needle move to the right.

So, I'm closing the book on the generator for now and will wait and see if battery stays charged.

Thanks again for everyone's help. It's great to be on this site! :beer:

Gary
Pilot Mtn. NC


Your mechanic buddy is wrong. 6 volts is the idle voltage of the battery. When the generator is working properly, the voltage is 7 to 8 volts.

With the lights on, the ammeter should show no discharge, as the generator will produce the majority of the current needed for the lights.

For a battery to charge, the potential has to be above the threshold to start the chemical reaction inside the battery. That is why 12 volt systems have a charging voltage of 14.8 volts.

I think your problem is with the voltage regulator, as it sounds like your generator is not receiving the voltage to work.

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Re: Ammeter not showing charge on 6 volt system

Postby Eugene » Fri Jul 29, 2016 6:00 pm

Before I made any final determination as to the apparent low charging voltage I would wait for results from the amperage test John M. outlined.

6.34 volts is a bit below the desired minimum. However, a charging 6.34 volts will being the battery up to 97% of full charge. More than sufficient to operate the tractor.

A just out of the store battery will only have about 80% of a full charge.

Unless I could find something specific, such as the electrical wiring problem JP described, I would leave the system along until it completely failed. Before I purchased an other regulator for $75- I would convert to 12 volt single wire alternator.
I have an excuse. CRS.

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Re: Ammeter not showing charge on 6 volt system

Postby Glen » Fri Jul 29, 2016 9:37 pm

Hi,
It is not really hard to adjust a Cub voltage regulator to change the voltage output. If your system is working, you can raise the voltage the generator is making.
Below is a pic showing what to do. Hook up your voltage test equipment so you can see the voltage the system has, and if the gen output is too low, bend the metal spring holder at the bottom end of the spring down slightly, this makes more tension on the spring. It takes only a tiny amount of bending to change the voltage output.
The older Delco regulators I have seen had an adjustment screw for it. The newer regulators you have to bend the metal.
You have to do this on the correct coil of wire, or side, it is not the side that controls the on and off for the charging system, but the other side.
You could also clean the points at the top of the coil of wire with a point file, the points burn after years of use. Wipe then off with a clean rag after filing them. :)
Attachments
Cub reg 2.jpg

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Re: Ammeter not showing charge on 6 volt system

Postby Matt Kirsch » Mon Aug 01, 2016 1:06 pm

Don't forget the rest of the system: Wiring and grounds. Good clean connections all around are necessary for proper operation.

Also, hit google and find "John T's Generator Troubleshooting Procedure" and print yourself a copy of that post from another forum. He has a very conclusive procedure for figuring out what's wrong with your system.

I personally do not trust the "test" that they perform on generators and alternators at auto parts shops. For some reason they ALWAYS test "good" no matter what.


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