Generator not charging on 1925 T

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CrandallJ
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Generator not charging on 1925 T

Post by CrandallJ » Sat Dec 04, 2021 8:50 am

I bought a rebuilt generator but doesn’t show a charge on ammeter. Checked all wiring and seems to correct. Input wire to generator indicates 6.3 volts. Stud on generator no indicating any voltage. Do I need to flash the generator? Cutout replaced but didn’t solve problem.


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Re: Generator not charging on 1925 T

Post by Scott_Conger » Sat Dec 04, 2021 10:03 am

The only person you should be communicating with is the guy who sold you the rebuilt generator
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Humblej
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Re: Generator not charging on 1925 T

Post by Humblej » Sat Dec 04, 2021 10:20 am

I agree with Scott. But regarding your wiring and ammeter, does the ammeter show a discharge with the lights on?

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Re: Generator not charging on 1925 T

Post by TRDxB2 » Sat Dec 04, 2021 10:31 am

crandalj wrote:
Sat Dec 04, 2021 8:50 am
I bought a rebuilt generator but doesn’t show a charge on ammeter. Checked all wiring and seems to correct. Input wire to generator indicates 6.3 volts. Stud on generator no indicating any voltage. Do I need to flash the generator? Cutout replaced but didn’t solve problem.
Yes, talk to the seller. But "input wire to the generator.." isn't something you want to say to them. What do you mean by that , wire to the cut-out from that battery?
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Re: Generator not charging on 1925 T

Post by Norman Kling » Sat Dec 04, 2021 11:21 am

Have you flashed the generator? It's easy to do, just take a hot wire from the battery and quickly touch it to the post on the generator. You might do it several times, but only leave it on for a second. Then try out the generator again through the cutout. Sometimes when a generator sets idle a long time, the residual magnetism in the generator deteriorates and it does not put out enough current to operate the cutout or even pass through a diode, so the flash will build up the magnetic field enough to start the generator working. If you use the car often, the magnetism should remain enough so you will not need to flash.
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Re: Generator not charging on 1925 T

Post by Scott_Conger » Sat Dec 04, 2021 11:41 am

A rebuilt generator should not need to be flashed. Ever. The generator should build up on its own. Flashing is simply strong-arming the generator to overcoming a fault that was not remedied during the rebuild, meaning if that "fixes" it, then the generator is marginal at best.

Again, despite lots of well meaning people you should not be seeking advice from anyone but the person who rebuilt the generator. If there is or ever was, a warranty on this thing, you may easily be advised to, or accidentally do something which may damage it.
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Re: Generator not charging on 1925 T

Post by Art M » Sat Dec 04, 2021 1:47 pm

I agree with Scott. Don't monkey with the generator. But make sure everything beyond the generator is in working order. This can be problematical in itself, especially the cutout.
If you have access to a known working generator, take advantage of it. You might have a friend with one willing to try.

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Re: Generator not charging on 1925 T

Post by John kuehn » Sat Dec 04, 2021 1:54 pm

Don’t try to fix the generator if it doesn’t charge. Call or text the seller and ask if it was charging when he sent it to you.

He should have tested it before he sent it to you.
If he says he did then ask him what to look for since it’s not charging for you. Don’t wait to long to inquire about it but talk to or text him as soon as you can.


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Re: Generator not charging on 1925 T

Post by CrandallJ » Sat Dec 04, 2021 2:06 pm

Thanks for the inputs. Sent an email to company. Reputable dealer that most of you may know. I did remove the cutout and the generator and it is shorted to ground. Assume this is bad.

Thanks


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Re: Generator not charging on 1925 T

Post by Ron Patterson » Sat Dec 04, 2021 2:20 pm

Crandalj
STOP!
Does your car have a reverse current relay type cutout or Fun Projets Voltage regulaor?
You need to find out the answer to this before you start trouble shooting. If you "flash" a generator that is using a Voltager Regulator you will be lighting a match to a $75 VR and you wont be able to find a new one beacuse they are no longer made.
Take the device mounted on top of the generator off and lay it on the table bottom up and take a photo. Post that photo here someone will tell you what you have.
If your car actually has a relay type cutout installled, go ahead and short across the cutout wih a piece of wire. It might start working.
Give me a call I may be able to help. The indication that you have no voltage at the generator terminal with the engine running is important .
Ron Patterson


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Re: Generator not charging on 1925 T

Post by Ron Patterson » Sat Dec 04, 2021 2:21 pm

Crandalj
That is not "bad", the generator has a very low internal resistance to the case ground.
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Re: Generator not charging on 1925 T

Post by TRDxB2 » Sat Dec 04, 2021 4:36 pm

Fun Projects Voltage Regulator vs typical cutout
Attachments
vr id.jpg
vr id.jpg (12.55 KiB) Viewed 4008 times
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Re: Generator not charging on 1925 T

Post by Ron Patterson » Sat Dec 04, 2021 7:09 pm

CrandalJ
The information Frank Brandi provided will help you to determine what you actually have: a reverse currewnt cutout OR Voltage Regulator.
I thought a lot about your problem today and I would like to talk to you. Call 231-348-5085
If you have a cutout and no voltage at the generator terminal bolt with the engine running at a moderate speed there only two things that can be wrong. Either the generator is not starting (building up) by itself (see the following:https://modeltfordfix.com/adjusting-the ... patterson/ OR the brush plate lead was not originally correctly set by the generator rebuilder.
Nothing would surprise me.
We can talk more about this when you call.


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Re: Generator not charging on 1925 T

Post by Jerry VanOoteghem » Sun Dec 05, 2021 7:52 am

Crandalj,

My advice is to take Ron up on his offer to help you. He is the guy when it comes to T generators.


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Re: Generator not charging on 1925 T

Post by CrandallJ » Sun Dec 05, 2021 12:02 pm

Attaché is a photo of the cutout I’m using.


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Re: Generator not charging on 1925 T

Post by CrandallJ » Sun Dec 05, 2021 12:56 pm

[image][/image]

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Re: Generator not charging on 1925 T

Post by TWrenn » Sun Dec 05, 2021 1:50 pm

Thats why I love my alternator! Its a "daily driver" albeit a show quality restoration, but I got sick of fighting with the generator, :twisted: most of which can't even keep the headlights bright at idle. Not a problem with the alternator. Purism be damned this time!! :lol: :roll:

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Re: Generator not charging on 1925 T

Post by TWrenn » Sun Dec 05, 2021 1:51 pm

I forgot to mention FWIW this is on my '25/26 "overlap" Fordor.


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Re: Generator not charging on 1925 T

Post by CrandallJ » Fri Feb 04, 2022 3:21 pm

Ron,
I tried jumpering the cutout but it was like jumping the 6.3 bolts to ground. The ammeter pegged negative.


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Re: Generator not charging on 1925 T

Post by Scott_Conger » Fri Feb 04, 2022 4:11 pm

Two months after installing a rebuilt generator that won't work, you've received offers of off-line help from a pro, been advised to speak directly with the repairman that you bought it from to get warrantee satisfaction (which you apparently have not), and you are still asking for help on a public forum.

Why?
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Re: Generator not charging on 1925 T

Post by Jerry VanOoteghem » Fri Feb 04, 2022 5:16 pm

crandalj wrote:
Fri Feb 04, 2022 3:21 pm
Ron,
I tried jumpering the cutout but it was like jumping the 6.3 bolts to ground. The ammeter pegged negative.
May be obvious, but was the engine running when you jumped the cutout?

And, as Scott mentions above, you really need to speak with the rebuilder...


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Re: Generator not charging on 1925 T

Post by Altair » Fri Feb 04, 2022 11:12 pm

Sometimes we tend to get too technical, my generator failed to charge and I could see a slight blackish film on the commutator that I suspected was oil. I dipped a small paint brush in some gasoline (just the tip) and trained it on the commutator while it was running, the generator started charging immediately, this will not cause a catastrophic explosion or burn the block up, the amount of gasoline is equal to about 1/50 of a tea spoon. By the time the generator restarts charging the gasoline has evaporated, it only takes about 1-2 seconds.


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Re: Generator not charging on 1925 T

Post by CrandallJ » Sat Feb 05, 2022 10:03 am

I bought the generator replacement from Lang’s old Auto Parts in Oct timeframe. It has never worked. I’ll call them Monday. Any suggestions on where I could send it for repair? Thanks.

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Re: Generator not charging on 1925 T

Post by TRDxB2 » Sat Feb 05, 2022 10:53 am

crandalj wrote:
Sat Feb 05, 2022 10:03 am
I bought the generator replacement from Lang’s old Auto Parts in Oct timeframe. It has never worked. I’ll call them Monday. Any suggestions on where I could send it for repair? Thanks.
Lets start from the beginning. You have explained what you have done but its necessary to understand exactly what your working with.
What prompted you to buy a generator in the first place, was the one on the car not charging or some other reason?
Which generator did you buy from Lang's they offer a rebuilt and a "best Quality"?
Is the cutout you have your original one or is it one you purchased with the generator? If purchased which one was it, solenoid or diode?
Have you tested the cutout to see if it is working properly.

You originally stated "Input wire to generator indicates 6.3 volts. Stud on generator no indicating any voltage." If you meant by "input wire" on the generator was from the battery and there was no voltage on the generator stud to the cutout AND the car was not running - then that would be expected since the cutout is to block the reverse voltage going from battery to generator.
If its your old cutout and your old generator was not working, the problem could be with the cutout and not the generator and that's why things still don't work. There is no need to flash a diode cutout or Voltage regulator. If it was one of those (old or new) your flashing killed it.

Bottom line- your problem could be with the cutout and not the generator. If its a solenoid type, too wide a contact point gap will prevent it from working, flashing doesn't solve that. If points were stuck, it would drain your battery and/or ruin the generator. If its a diode or VR type, a failure could end in similar fashion.
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Re: Generator not charging on 1925 T

Post by Norman Kling » Sat Feb 05, 2022 11:51 am

Ron Patterson knows what he is doing! Take him up on his offer.
Norm


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Re: Generator not charging on 1925 T

Post by Jerry VanOoteghem » Sun Feb 06, 2022 4:07 pm

crandalj wrote:
Sat Feb 05, 2022 10:03 am
I bought the generator replacement from Lang’s old Auto Parts in Oct timeframe. It has never worked. I’ll call them Monday. Any suggestions on where I could send it for repair? Thanks.
Let's see what Lang's will do. They have an excellent reputation!


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Re: Generator not charging on 1925 T

Post by Altair » Mon Feb 07, 2022 2:01 am

A generator can be tested on the engine with the cutout disconnected, With the engine running there should be voltage available from the terminal and the voltage is only limited to the RPM, Your battery would be happy 7 - 7.5 volts but with the cut out disconnected the voltage will be much higher as the RPM increase. I have a 54 Studebaker and I am going through the same issues after repairs were done (stuck brush) on the test bench it produced 40 amps at high RPM, however only 7.5 at the battery in the car through the regulator. With the regulator disconnected the volts increased to 30+ relative to the RPM. You can operate some DC power tools by disconnecting the regulator and controlling the RPM to attain the required voltage, there are some limitations with this method.


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Re: Generator not charging on 1925 T

Post by Scott_Conger » Mon Feb 07, 2022 10:36 am

Limitations indeed! Hot lead flying around will pretty much ruin your day, not to mention the generator armature.

Crandalj, call Lang's before you go from an inoperative generator to a ruined generator, assuming that has not happened already.

These sorts of discussions remind me why I no longer remanufacture generators for sale. Whenever I get the itch to, I refer back to one of these threads and my passions are cooled for another year or so.
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Re: Generator not charging on 1925 T

Post by Ron Patterson » Mon Feb 07, 2022 10:47 am

I suggest no one try Altairs generator test.
No useful information can be obtained by doing so.
In doing so your just a few steps away from catastrophically destroying your generator.
DON'T test a third brush regulation generator in that manner!
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Re: Generator not charging on 1925 T

Post by TRDxB2 » Mon Feb 07, 2022 11:30 am

crandalj wrote:
Sat Dec 04, 2021 8:50 am
I bought a rebuilt generator but doesn’t show a charge on ammeter. Checked all wiring and seems to correct. Input wire to generator indicates 6.3 volts. Stud on generator no indicating any voltage. Do I need to flash the generator? Cutout replaced but didn’t solve problem.
Well its been 2 months since you first reported your generator issue. Many have mentioned contacting Lang's along the way and you said that you would be contacting them Today. Not sure which generator you purchased from them but both state that they are tested. A warranty period is not mentioned. If I were Lang support and read through this dialog , I would offer testing it with shipping both ways at your expense. The reason ... your attempts to solve the problem could have damaged it and could offer a discounted refurbish price.
If it tests correctly, what then? Did you send the cutout also?
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Re: Generator not charging on 1925 T

Post by Altair » Tue Feb 08, 2022 1:11 am

There is a local electrical automotive shop that has been in business for decades and regularly tests generators by turning them on a bench with an electric motor at high RPM for an efficiency test. In some cases the field terminal is jumpered back to the housing for a spark test, in other cases the terminals are connected to a meter. This procedure is the same as if the test was done on the engine, on the bench the electric motor and belt drives the generator and on the engine the engine turns the generator. The procedure on the bench is exactly as on the engine. High RPM is not necessary just e little above idle will give you a reading if it is or isn't charging. Nothing catastrophic will happen and there will not be melting lead, smoke or fire and it will not destroy the generator. In an emergency where two vehicles were side by side and one vehicle's battery was dead and there were no jumpers available. The vehicle with the good battery was started and the RPMs were brought up to about 3000 then the battery was removed and it continued to run on the generator, the headlights were on at double brilliance. The battery from the dead vehicle was removed and replaced with the charged battery, that vehicle was started brought up to 3000 RPM and the batteries were swapped back to their respective vehicles. Now both vehicles are running and the RPM returned to normal and continued home. There was no melting lead or commutator flying apart or any damage to either generator. This is about the most abuse one could give to a generator. These units are substantially built and can take a lot of abuse before failing.


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Re: Generator not charging on 1925 T

Post by Ron Patterson » Tue Feb 08, 2022 9:16 am

David M.
I know you think your right, and you are for SOME generators. The T generator is not robust like other generators you have experience with and will not survive much abuse. Automobiles from the late thirties, fortys and fiftys are full field controll type and you can run them without a load and not harm them, but not a Model T generator.
Let me explain; the Model T generator is third brush regulated constant current source and MUST be connected to a load or the "building up" (starting to charge) process with continue uncontrollably producing 30+ volts which is impressed on the armature and field winding curcuits. The result is the armature gets so hot centrifigal force slings the solder out of the winding connections like Scott Conger suggested or, depending upon the setting of the third brush, burns the field winding open circuit.
If you think I am wrong about this, remove the cutout from your Model T and drive it for a while?
The third brush regulation type generator was last used on American automobiles in the late 1930's and most generator repair shops simply have no experience with them. I rebuilt Model T generators for 25 years and can tell you that if you have Model T generator trouble the LAST place you want to take it to a modern day generator repair shop. Take it to a person who understands how a T generator works and has appropriate repair and testing apparatus.
Like so many things Model T, the generator is a trap for logical people, by that I mean it looks just a litle too simple. In truth it is not and one false move it is toast.
Good luck.
Ron Patterson


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Re: Generator not charging on 1925 T

Post by TXGOAT2 » Tue Feb 08, 2022 9:49 am

The T generator is indeed very different from the later ones. I've seen later type 6 and 12 volt generators survive horrific abuse and continue to operate. In the case of the Model T generator, a feedback situation develops which causes a runaway overcharging situation. Some older style electric motors behave in a similar fashion, and they must have a load applied to the shaft or they will run away and destroy themselves by overspeeding. This type of motor is no longer in wide use, and it was common practice to install a mechanical governor of some type on them when they were. I used to play with a small, brush-type sewing machine motor when I was a kid. The thing would begin revving up when plugged in, and would continue gaining speed until it was literally howling. It developed very strong gyroscopic forces due to the extreme RPM. It's a wonder it didn't fly apart and take my hand off. Its small size and low power were the only things that prevented it from flying to pieces. At some point, windage and friction and perhaps reverse EMF kept it from going any faster. To sum up, experience with auto generators of the 1940s and 1950s does not provice reliable guidance for dealing with Model T generators.


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Re: Generator not charging on 1925 T

Post by Art M » Tue Feb 08, 2022 11:39 am

A local starter generator shop will work on model t electrics. He determines what it needs and has the customer order the parts. He does not stock or order any parts for antique cars.
I rebuild my own starters and generators otherwise I would use this shop.

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Re: Generator not charging on 1925 T

Post by Altair » Tue Feb 08, 2022 3:24 pm

OK, I will step back a notch and accept your comments. But I don't think testing a generator on a Model T slightly above idle will cause a catastrophic failure.

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Re: Generator not charging on 1925 T

Post by ABoer » Tue Feb 08, 2022 3:34 pm

To tests Generators I use this .
Toon
IMGP2748.JPG


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Re: Generator not charging on 1925 T

Post by Jerry VanOoteghem » Tue Feb 08, 2022 4:23 pm

Altair wrote:
Tue Feb 08, 2022 3:24 pm
OK, I will step back a notch and accept your comments. But I don't think testing a generator on a Model T slightly above idle will cause a catastrophic failure.
Yes, but anything that's essentially detrimental to the generator is not any kind of a valid test either.


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Re: Generator not charging on 1925 T

Post by Altair » Wed Feb 09, 2022 10:09 pm

My last and final comment, what is the difference between turning the generator on a bench device with an electric motor and turning the generator on the motor?


speedytinc
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Re: Generator not charging on 1925 T

Post by speedytinc » Thu Feb 10, 2022 8:19 am

Altair wrote:
Wed Feb 09, 2022 10:09 pm
My last and final comment, what is the difference between turning the generator on a bench device with an electric motor and turning the generator on the motor?
A correctly made test stand. None. Both ways should have a battery that matches the final voltage to the car as part of the test station.


Jerry VanOoteghem
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Re: Generator not charging on 1925 T

Post by Jerry VanOoteghem » Thu Feb 10, 2022 12:38 pm

Altair wrote:
Wed Feb 09, 2022 10:09 pm
My last and final comment, what is the difference between turning the generator on a bench device with an electric motor and turning the generator on the motor?
No difference at all. That's how I test mine, on a bench device. The issue was with running the generator with no load applied. Doing that, either on a car, or on a test stand, can/will injure the generator.

FWIW, I had an alligator clip jump off the generator terminal while running on a test stand, (i.e. no load applied). The load on the test stand motor was so great that it nearly stalled the unit. Goes to show the energy being generated internal to the generator that it should stall out a 1/4hp motor.

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