Amp Meter discharge, but no charge?

travis_towle · Post by **travis_towle** » Sun Oct 29, 2023 1:23 am

I am having an issue that I have not been able to track down a solution yet.

I found this topic from 2016 and it’s just like mine but I never saw the fix so I will add to it for my problem:

Below are the facts of what I have done or checked thus far:

1. New 6 V Battery
2. Braided negative battery cable to frame.
3. New battery cable from battery to starter switch.
4. Brand new engine by mike bender.
5. Cutout is in place (pretty sure it’s a cutout not a new diod mod).
6. Installer Replaced 2 years ago and less then 2 miles on the engine since, the Generator with new one probably from Lang’s.
7. Adjusted the 3rd brush with no change at Amp meter.
8. All wiring is new.
9. Meter Testing with car NOT running, and key OFF shows 6 volts at front of cutout and 0 on back (generator mount).
10. Flashed he generator.

With car off or running, when I turn on headlights, the amp meter does show a discharge. No matter what I have done thus far, I am not able to get a + charge displayed on amp meter no matter what engine speed.

I am open to suggestions and guidance.

Travis E Towle
Topeka, Kansas

Post by **Moxie26** » Sun Oct 29, 2023 1:43 am

Travis, welcome back to the forum!... The cut out you have on your generator may be in question, if it is a real cut out or is it a voltage regulator from fun projects? Flashing the generator with a fun projects, voltage regulator will cook your voltage regulator , will give the same results as you're getting with constant discharge. Looking at your generator comutator surface,... is it shiny copper yet or has it a gray to black look to it? Cleaning that commutator with some light sandpaper while it's running may reestablish your working generator. How many times did you readjust the third brush for a charge change? If your rebuilt generator did not include new insulating gaskets , you may have a grounding fault on that third brush which would result in getting no charge in the generator. There are a couple variable factors that you have to address to get an answer. Good luck!!

travis_towle · Post by **travis_towle** » Sun Oct 29, 2023 2:24 am

I highly doubt the guy who installed my engine, and put the rebuilt generator even knows what fun projects is. I’m 99.9% sure this is a regular cut out. It’s painted black, old and pitted looking. He basically would have bought anything he didn’t have in his storeroom from Lang’s. He is a old car builder but not a T expert. Just knows enough to be dangerous.

When running or driving my amp gauge just stays at (0) unless I turn on the lights then it goes ( negative and stays until I turn them back off then back to zero).

What is my generator communicating surface? Is this the area under the removable band?

I took the band off, loosened up the nut inside and turned the third brush back and forth, it was all the way engaged (pushed towards the engine). I slid it to the center, tightened and restarted the car, no change. I then moved it back towards the engine all the way, no change.

What are these insulating gaskets you are talking about? I didn’t install the generator so I would need to check and see if the installer did ~ he might not have.

Travis

Post by **Jerry VanOoteghem** » Sun Oct 29, 2023 7:22 am

Travis,

With the engine running and someone to look at the ammeter, take a piece of wire and bridge across the cutout. In other words, bypass the cutout. See if you don't show a charge when doing so. If you do, then either your cutout is bad or your generator is not able to make enough current to energize the cutout. If bypassing the cutout shows a charge, then note whether or not it keeps charging when the jumper wire is removed.

Post by **Moxie26** » Sun Oct 29, 2023 7:34 am

Good morning Travis... That third brush is mounted on insulating gaskets. When that generator was purchased how much of it was rebuilt if any?.... I have come across rebuilt generators that look like they've been repainted, and that's all. With moving that third brush, loosening to a degree that it would drag when moved before, tightening has a probability of breaking that insulator and having that third brush ground out by touching metal in the brush retaining ring... Original gaskets will dry out, become brittle from age, engine heat and cold cycles and moving that brush will change generator output and none if grounded out...... The commutator is visible when the band is taken off and gives access to moving that third brush. Would there be someone in your local chapter that could have a hands-on check of that generator?

Norman Kling · Post by **Norman Kling** » Sun Oct 29, 2023 9:35 am

What Jerry said, is what I would do. I have a diode cutout, but NOT a voltage regulator. If the car has been setting for a long time without being driven, the generator will lose residual magnetism which is necessary to start it charging. The wire bypasses the cutout which will allow the battery to recharge the magnets in the generator. It only takes a few seconds to do this.
Norm

Post by **Woody23** » Sun Oct 29, 2023 10:44 am

Hello Travis,

I rebuild generators and have a bench tester I made to quickly diagnose issues. I can walk you though a few tests if you have a basic voltmeter.

Shoot me a message if you want to take a few measurements.

David

Dwtworks@gmail.com

Williamston T Works (Facebook)

Post by **Moxie26** » Sun Oct 29, 2023 11:52 am

Travis... How long or when did this problem start?

Ron Patterson · Post by **Ron Patterson** » Sun Oct 29, 2023 12:44 pm

Travis
I only work on Model T electrical issues.
Your problem description provides clues that here are only three areass you must check to isolate your trouble.
I will help you if give me a call at 231-348-5085.
Ron Patterson

Post by **Jerry VanOoteghem** » Sun Oct 29, 2023 2:01 pm

Travis,

It would be wise to take Ron P. up his generous offer of help. He will definitely get to the source of trouble.

(No disrespect meant towards others who have offered help as well!)

Post by **speedytinc** » Sun Oct 29, 2023 2:10 pm

Generator output should be checked @ the output terminal while running.
Rule out a bad cut out & other possible issues further downstream.
When you find the generator isnt working, pull & send to a competent rebuilder.

Post by **J1MGOLDEN** » Sun Oct 29, 2023 5:30 pm

The ammeter accuracy should also be checked by reversing the leads and see if the readings reverse the same amount.

BobUkPipedream · Post by **BobUkPipedream** » Sun Oct 29, 2023 5:32 pm

Just a slightly silly thought, bad amp meter? Depending on the type, they ara bit fragile. I have a nice old original and was about to use it when I noticed that the cork insulating washers are all broken up and falling out with each slight movement.I will use my cheaply manky new one till I can fix the original.

Will watch with interest as I just fitted a secondhand generator that has been sat for a couple of years and I am about 2-4 weeks from first engine start I am hoping to get lucky and have it all work, but so far I have been very unlucky with everything, it has been a struggle.

Post by **speedytinc** » Sun Oct 29, 2023 5:39 pm

BobUkPipedream wrote: ↑
Sun Oct 29, 2023 5:32 pm
Just a slightly silly thought, bad amp meter? Depending on the type, they are a bit fragile.

"The ammeter shows discharge with the lights on". It's fine. It's possible that the generator output is wired such that it is not going thru the meter, but directly to the battery. The real test is @ the generator output terminal.

travis_towle · Post by **travis_towle** » Sun Oct 29, 2023 6:10 pm

Update:

I called Ron and he walked me through some things ~ so extremely happy for guys like him! He is going to send me an email with some testing I need to do to focus in on the problem. He also suggested I buy a Nu-Rex SEMI-CONDUCTOR CUTOUT in the morning to help focus down the problem further, I’m going to do that.

The guy who dropped my engine in (and repaired this smoke and water damaged car) while I was rebuilding my fire destroyed house also said he is 95% sure the generator came from Lang’s 2 years ago, he thinks it is the original cut out that was with my car parts, he said today they didn’t adjust anything and did not know if it had a third brush, they just fired the car up after they installed everything. I was double checking all their work when I found this problem.

I’ll give further information as we narrow it down. It’s been 20 years almost to the day getting this from a junk yard non running car to a concourse show car and I’m excited to be finishing up and able to learn how to drive it.

Travis

Norman Kling · Post by **Norman Kling** » Sun Oct 29, 2023 6:21 pm

I don't think this was covered above. A Model T battery has a negative ground to the chassis and positive cable to starter switch and from there to the ammeter and from ammeter to cutout. The Model T battery is opposite with positive ground and negative to generator. If you have the battery connected backward it would cause this problem or if the cutout is for a Model A it would not work on a T.
Norm

Post by **TRDxB2** » Sun Oct 29, 2023 6:22 pm

travis_towle wrote: ↑
Sun Oct 29, 2023 6:10 pm
Update:

I called Ron and he walked me through some things ~ so extremely happy for guys like him! He is going to send me an email with some testing I need to do to focus in on the problem. He also suggested I buy a Nu-Rex SEMI-CONDUCTOR CUTOUT in the morning to help focus down the problem further, I’m going to do that.

The guy who dropped my engine in (and repaired this smoke and water damaged car) while I was rebuilding my fire destroyed house also said he is 95% sure the generator came from Lang’s 2 years ago, he thinks it is the original cut out that was with my car parts, he said today they didn’t adjust anything and did not know if it had a third brush, they just fired the car up after they installed everything. I was double checking all their work when I found this problem.

I’ll give further information as we narrow it down. It’s been 20 years almost to the day getting this from a junk yard non running car to a concourse show car and I’m excited to be finishing up and able to learn how to drive it.

Travis

Forget about the NY-Rex cutout & buy a Voltage Regulator now available from the Forum's Administrator Jeff http://www.vintageregulators.com
Also does starters & generators!

Post by **Moxie26** » Sun Oct 29, 2023 7:42 pm

I agree, Jeff Stevenson and a group of dedicated people have put forth a very reliable voltage regulator for the Model. T three brush generator....www.vintageregulators.com

Post by **Jerry VanOoteghem** » Sun Oct 29, 2023 7:59 pm

Travis,

Listen to one voice.

Rod Petrie · Post by **Rod Petrie** » Mon Oct 30, 2023 3:59 pm

I have the exact same problem. New rebuilt generator from Langs, new VR from Jeff, new wiring and repro ammeter. Going down the road I get +5 but when I turn the headlights on it shows -10. Do I dare advance the 3rd brush any more?

Post by **Moxie26** » Mon Oct 30, 2023 4:05 pm

"I have the exact same problem. New rebuilt generator from Langs, new VR from Jeff, new wiring and repro ammeter. Going down the road I get +5 but when I turn the headlights on it shows -10. Do I dare advance the 3rd brush any more? "............... Your generator is working. What size headlight bulbs are you using ? .... and do you have one or two rear bulbs with stoplights & directional signals ?? More bulbs on the lighting circuit will take more power to work as installed...... Is the battery fully charged before using in car ?, if not the generator will need time to charge battery as you drive.

Norman Kling · Post by **Norman Kling** » Mon Oct 30, 2023 4:16 pm

With a voltage regulator, you should follow the instructions that came with it or contact the manufacturer to find out if it is OK to raise the output of the generator. I would think it would be ok because that is what the VR is supposed to take care of and if the generator is set too low, the regulator cannot raise it. But that is just my idea since I do not use those.

Ron Patterson said to use a semi-conductor cutout. That is what I use, and I can control the output by moving the third brush toward the block to raise the output and away from the block to lower it.

Where you set the output depends on how much you drive with lights on. If very rarely at night or just a few blocks such as going from a hotel to a restaurant on a tour, you can leave the setting as is. But if you drive for long distances with lights on raise it so it will read zero with the lights on. That will still give you more than enough to recharge the battery after starting, and if you drive long distances during daylight hours, just turn on the lights. Remember to turn them off when you park.
Norm

Luke · Post by **Luke** » Mon Oct 30, 2023 4:33 pm

Rod Petrie wrote: ↑
Mon Oct 30, 2023 3:59 pm
I have the exact same problem. New rebuilt generator from Langs, new VR from Jeff, new wiring and repro ammeter. Going down the road I get +5 but when I turn the headlights on it shows -10. Do I dare advance the 3rd brush any more?

Assuming your meter to be accurate then you could increase the available charge current since 5A is well under the maximum possible at 6V, although it would be better if you didn't need to.

It is possible you have an issue, -10A reading, assuming a +5A input suggests a total lighting system draw of 15A, which at 6V is 90W. This may be ok if that's what you expect from the bulbs you're using, but Robert raises a good point.

For me, particularly given the age of wiring and electrical components in all my old vehicles, I have installed LED tail and head lamps which markedly reduce the total lighting current draw. This means that the constant charge current can be significantly reduced for those without regulators, and maximum charge current reduced for those with regulators. Obviously this results in a system improvement for daytime running as well as nighttime as it is easier on the battery + wiring (with an added bonus of better lighting!).

I realise this solution isn't for everyone, hence I simply offer it as an explanation of how this polymath has dealt with the otherwise vexing issue of aging electrical infrastructure. Apart from that it's good to read that you've assisted the battery by introducing a regulator, and that at this point you've kept the max charge current to a minimum.

Luke

Post by **TRDxB2** » Mon Oct 30, 2023 5:53 pm

Understanding the purpose of a cut-out..... trying to keep it simple
The purpose of the cut-out is to prevent battery voltage from running the generator as a motor. The original cut-outs were electromechanical switches that would open or close based on generator output by setting a setting its points to open/close at a specific voltage. So when the voltage of the generator is greater then the voltage of the (correction per Jerry V below not battery but point setting, the magnetic coils on the cutout will close a switch connecting the generator to the battery.

: indexfordt2.jpg (14.16 KiB) Viewed 7018 times

--
If that voltage threshold is not reached the points would remain open and there would be no current reading. As a result the ammeter would not register a positive amperage value. Since the original cut-outs required a voltage source to operate when they fail it could be that the points need to be set or the voltage from the generator is less than that of the battery.
An electronic cutout using a diode serves the same purpose but operates more of a check valve than a mechanical switch.
--
A Voltage Regulator includes the function of a cutout as well as regulating the output voltage to the battery to prevent it from overcharging. The Model T generator design, 3rd brush, means that a special VR is needed not just any 6volt one
--
The ammeter is registering amperage load on the system. Theoretically, you could get a positive reading with lights on if the 3rd brush was set to a value greater than what the demand of the electrical system is. The recommended setting of the 3rd brush is 5 to no more than 10 amps. Filament bulbs take 1.5 or more amps. That is why many change to led bulbs that draw less than .5amp - do the math
--
Bottom line - the ammeter just indicates if the generator and cutout are operating correctly.

Post by **Jerry VanOoteghem** » Mon Oct 30, 2023 6:20 pm

TRDxB2 wrote: ↑
Mon Oct 30, 2023 5:53 pm
So when the voltage of the generator is greater then the voltage of the battery, the magnetic coils on the cutout will close a switch connecting the generator to the battery.

The initial generator output does not have to be greater than the voltage of the battery. It only needs to be enough to close the cutout contact points, independent of the battery voltage. As your diagram shows, the battery is totally independent of the generator/cutout circuit until the points close.

Post by **TRDxB2** » Mon Oct 30, 2023 8:23 pm

Jerry VanOoteghem wrote: ↑
Mon Oct 30, 2023 6:20 pm

TRDxB2 wrote: ↑
Mon Oct 30, 2023 5:53 pm
So when the voltage of the generator is greater then the voltage of the battery, the magnetic coils on the cutout will close a switch connecting the generator to the battery.

The initial generator output does not have to be greater than the voltage of the battery. It only needs to be enough to close the cutout contact points, independent of the battery voltage. As your diagram shows, the battery is totally independent of the generator/cutout circuit until the points close.

Opps.... Thanks for the correction

Post by **Jerry VanOoteghem** » Mon Oct 30, 2023 8:48 pm

TRDxB2 wrote: ↑
Mon Oct 30, 2023 8:23 pm

Jerry VanOoteghem wrote: ↑
Mon Oct 30, 2023 6:20 pm

TRDxB2 wrote: ↑
Mon Oct 30, 2023 5:53 pm
So when the voltage of the generator is greater then the voltage of the battery, the magnetic coils on the cutout will close a switch connecting the generator to the battery.

The initial generator output does not have to be greater than the voltage of the battery. It only needs to be enough to close the cutout contact points, independent of the battery voltage. As your diagram shows, the battery is totally independent of the generator/cutout circuit until the points close.
Opps.... Thanks for the correction

No problem. Happy to help.

Post by **AdminJeff** » Thu Nov 02, 2023 1:43 am

Thanks for the plug guys, but first things first. Diode Cutouts and voltage regulators don't magically fix T generators that aren't working properly. Start there and get that working first. Then add the toys!

Jeff

Post by **AdminJeff** » Thu Nov 02, 2023 2:02 am

Rod Petrie wrote: ↑
Mon Oct 30, 2023 3:59 pm
I have the exact same problem. New rebuilt generator from Langs, new VR from Jeff, new wiring and repro ammeter. Going down the road I get +5 but when I turn the headlights on it shows -10. Do I dare advance the 3rd brush any more?

My regulators can handle whatever current the generator puts out. The Diode in the regulator is dual 30Amp which means it can safely handle 60A and uses the regulator base as a heat sink. It's really up to you (and your generator) how high you want to set the charge current. Just realize that the higher the current output, the more stress you put on the generator, and the sooner it's likely to fail. All electronics fail at some point. Everything is a compromise and setting optimum charge current depends on how you drive your car and what the current draw is. Setting the current to 1-2 A with your lights on should be ok. If you don't generally drive with your lights on then 5A charge current will get the job done. The regulator is there to prevent overcharging your battery no matter how much current your generator pumps out.

Model T gens are rated at 100watts. 100w/6v = 16A theoretical max output at 6v, assuming perfect everything. Operating them at 50% rated output (8A or less) will ensure a longer life!

Jeff

Ron Patterson · Post by **Ron Patterson** » Thu Nov 02, 2023 8:37 am

This trouble shooting method is absurd, I am outa here!

Post by **Moxie26** » Thu Nov 02, 2023 9:07 am

Chill out Ron, take a deep breath. Is this generator in front of you to have your hands on, or you getting the correct answers from the owner of that generator? I'm sure we all make mistakes on learning curves and it does take time to be perfect with that with the teacher in front of you with hands-on experience and repairs. I'm sure we've all been through the same learning experiences. Not one of us is perfect, we do learn from others.... That's Life !....... Now it's time for a little rest and another cup of coffee. Good morning everyone!

Post by **jab35** » Thu Nov 02, 2023 9:34 am

Too many cooks and not enough soup?

From my past experience, I'd follow Ron's advice. Respectfully, jb

Ron Patterson · Post by **Ron Patterson** » Thu Nov 02, 2023 10:30 am

Bob Jablonski
Cut the therapy room Psycho-Babble!
On the ninth post, I explained to Travis the only three potential areas of trouble and explained I would help him how to break the problem down to get two areas checked (wiring, which is commonly incorrectly installed and determine exactly what is inside that thing ? affixed to the top of the generator) and eliminated them to find the third and final mproblem. I recommended them in the order of simplicity and cost first.
I selected the Nu Rex Diode for trouble shooting becasue, it is an excellent product and it is not possible to properly troubleshoot the charging system with a VR installed.
When I help people I do it in a way so they learn the technique and can and can then pass on the knowledge.
I do not try to sell a product contrary to some others who icessantly post here extolling the viritue of their product.
What's next?, are we gonna be told to check the oil level in the rear axle and then see if the problem is fixed.
Lets get out of this do-loop nonsense.
C'Mon guys think!
Good by
Ron Patterson

Post by **Moxie26** » Thu Nov 02, 2023 11:59 am

After Travis receives his diode cut out and has time for installation and tests, I'm sure he will share and post his results.

travis_towle · Post by **travis_towle** » Thu Nov 02, 2023 2:41 pm

UPDATE:

I am waiting on my new diode cutout Ron told me to buy before going any further. It should be here today and I will start with Ron’s tests. I did check my wiring according to his diagram and it is showing correct. I will post an update for future reference. I am learning a ton from Ron’s writings and I can’t thank him enough!

I did start the car after checking the wiring and while learning how to use my new analog multimeter and noticed 6 volts in front of the cutout and nothing on the back, so in frustration I grabbed my wrench and flashed the crap out of the generator with the car running and checked it again, it was now showing power at the back of the cutout and showing a positive on the amp gauge. I let it run for about 2 minutes and shut it down. When I started the car later that night to check it again it was back to showing 0 at the back of the cutout, flashed it running again and it was back to showing power - being too cold that day to drive it I shut it all back down, my mind was telling me maybe I need to flash it and drive it around the park?. I decided to throw the car’s battery on the charger for the night with the in line safety battery cutoff switch off. That’s where I am right now, I figured I better just wait for the new diode cutout, install it and do the tests Ron told me to do, call him back and go from there.

Travis Towle
Topeka, Kansas

Post by **Moxie26** » Fri Dec 01, 2023 6:30 pm

Hey good evening Travis.. any solutions yet on your generator problem?

bobt · Post by **bobt** » Sat Dec 02, 2023 5:46 am

CHECK THE PIN THAT HOLDS THE GEAR ON THE END OF THE GENERATOR DRIVE SHAFT. (sorry, not yelling) I have an alternator on my 1926 and I had the same problem. The spiral pin was sheared. bobt

upman · Post by **upman** » Sat Dec 02, 2023 8:32 am

reading through this i might have missed it, but did anyone check to see if someone grounded the gen. so it would not burn out while testing the car r

travis_towle · Post by **travis_towle** » Thu Dec 07, 2023 7:34 pm

UPDATE:

I sent the generator off to Chris Mize and they put it on their bench spinner and was able to set the null point. I just installed it today and it’s working fantastic now.

Travis Towle
Topeka, Kansas

Post by **Moxie26** » Thu Dec 07, 2023 9:59 pm

Good news Travis... !