MTFCA Forum

1924 Coupe
i wasn't getting any reading on the ammeter so i watched a few videos and set my cut off switch to 6.5 (It was at like 2) and started moving the third brush. (toward the engine) Still nothing shows on the right side of the meter. I do think the meter is working as it shows a negative 1 when i turn on the lights (brights). Is my generator shot? I did try looking at all the connections. I took off the ignition / meter assembly and even tried to clean the gauge a little. Previously i had some trouble with the lights only the dims worked and after messing with them now only the brights work. I have no clue why. and before when only the dims worked the meter didnt move.
im thinking the generator doesnt work. wadda yall think?

I am thinking that you need to go out and turn on your headlights without the car running, and record the discharge showing on the ammeter

then start the car and turn on the headlights and record the discharge showing on the ammeter

this will tell you if the battery is receiving any charge from the generator without making you do a bunch of tests that you may or may not have the ability or desire to do right now

as for setting a "cut-off switch" from "2" to "6.5"...if you mean you have dismantled the cutout and changed it's mechanical settings, "2" cannot possibly be, and "6.5" is still too low. For any of these numbers to be real, I am misunderstanding what you have done or are trying to do.

Insulating gaskets between the adjustable brush holder and attaching brush assembly are probably dried out and cracked and electrically grounded. Snyder's and langs both have rebuilt brush assemblies with proper gaskets... Also sell the gaskets if you're willing to replace those yourself.

Scott_Conger wrote: ↑

Sat Jun 03, 2023 1:49 pm

I am thinking that you need to go out and turn on your headlights without the car running, and record the discharge showing on the ammeter

then start the car and turn on the headlights and record the discharge showing on the ammeter

this will tell you if the battery is receiving any charge from the generator without making you do a bunch of tests that you may or may not have the ability or desire to do right now

as for setting a "cut-off switch" from "2" to "6.5"...if you mean you have dismantled the cutout and changed it's mechanical settings, "2" cannot possibly be, and "6.5" is still too low. For any of these numbers to be real, I am misunderstanding what you have done or are trying to do.

Scott, headlights without the car running is 1 discharge. With the car running no change. minus 1... following the flivver channel you tube,(generator three part series), I removed the cutoff switch and with a variable power supply i tested when the switch would cut in. It was really low. 2 volts. so i adjusted the spring and had it cut in at 6 to 7 volts. After all this with the meter not showing any charge, i adjusted the third brush on the generator in the direction away from me almost all the way and still no charge.
thanks for caring Scott. I appreciate your knowledge and advise.

Moxie26 wrote: ↑

Sat Jun 03, 2023 2:00 pm

Insulating gaskets between the adjustable brush holder and attaching brush assembly are probably dried out and cracked and electrically grounded. Snyder's and langs both have rebuilt brush assemblies with proper gaskets... Also sell the gaskets if you're willing to replace those yourself.

Your diagnosis sounds logical. Ill give this a try but am not too confident on taking the generator apart. Would this be hard to do?
i have a question though, why would i sell the gaskets if they're no good?
Thanks for your response.

With the engine running try taking a jumper from the generator post across the cutoff to the battery side. If it shows a charge, your cutoff is not working. With the engine still running, take the jumper off and see if it still shows a charge. If so, the problem was with the residual magnetism in the generator. If the jumper makes no difference with the engine running, the problem is in the generator.
Norm

Bill

you likely do have generator problems, but for certain, you have ammeter problems.

with the engine turned off, and the lights "on", you should be showing a significant discharge of around 6A (to the "discharge" side of "0") or so depending on your bulbs. Then with the engine running and the lights "on" then whatever discharge is showing (lets say 4A discharge) then your generator would be putting out 2A of charge (the difference between 6A discharge and 4A discharge). This is just an illustration, not what you would necessarily expect to see.

so, the first thing I'd do is install a known GOOD ammeter in the circuit and see what is happening when you rerun the light test.

There is an awful lot of potential troubleshooting you may have to do on the generator and I'd highly recommend the purchase of the MTFCA Electrical handbook and study how to clean the commutator with the generator in the car, before delving into the bowels of the thing. Bad insulators on the brush plate is a very common problem, but so are gummy brushes and filthy commutator...might as well work on easy stuff before the tough stuff.

I think Bob's response to you got garbled and he is not suggesting you sell unused insulators, but that the vendors SELL just the insulators if you wanted to do the work yourself.

Remove the cover from the generator to expose the brushes and the armature take some fine sandpaper not emery cloth and sand, the armor sure until it's bright. You might be surprised that this does it. What if you times on the old generators I put the new cut out with the dilo in it in it, that will save the generator from burning up if the cut out quits that did not do it. The model T Ford Bible tells how to remove the old generator and to raise the third brush, put power to it to see if it turns and how to adjust it.

Bill,
You have a 100 year old generator with old insulation, worn brushes, worn commutator, old bearing, and with 100 years of dirt, grime and abuse. Let me suggest that the fixes in the Ford Service Manual and advice from MTFCA Forum members may be good for a healthy generator, but you are probably not starting with a healthy generator. The average bear does not have the tools, parts, and skill to rebuild a model T generator. My suggestion is to get a professionally rebuilt generator. There are several reputable rebuilders advertised in the MTFCA Vintage Ford and MTFCI Model T Times, I can recommend Brent Mize from my personal experience.

The cutout is merely an electromagnet that opens or closes the circuit to the battery. It either works, is stuck open, or stuck closed. I have never heard of anyone trying to adjust one to meter charging, that is the job of the third brush.

Headlights work on but not dim, then dim but not on. You may have ground issues, switch issues, wiring issues...any, some, or all of those problems. A 6 volt power supply and a test light will confirm where your problem(s) is/are. light switch/ignition switch is made from laminated cardboard, they warp, rot, and wear out over time.

With a healthy electrical system, the ammeter should show a neg 8 to neg 12 amps with the headlights on and the engine not running, neg 4 to neg 8 amps with the engine running and the generator working. A pos 6 to pos 8 amps with the engine running and the lights off.

Minor corrections/clarifications:

cutout allows voltage/current to the battery once the generator output reaches about 7.2V and conversely ensures its isolation from the battery once output falls below a certain level (above 6.3V). It most certainly can be adjusted for output, though it is typically only needed following repair or dressing of the points. If someone has dorked around with one without knowledge of what they are doing, readjustment will almost certainly need to be done. In fact a gentleman less than 2 weeks ago was advertising refurbished/readjusted regulators here on the Forum. Finally, the cutout has no bearing on the current output of the generator (only the voltage at which it pulls in).

advice:

with enough education and understanding of the device (MTFCA Electrical Manual), adequate tools (not everyone will have them) and some good luck that the armature has not thrown solder, the generator is repairable by a determined individual. Once working, how much on-the-road-aggravation it will cause will be determined by the quality of the work performed. It's not for everyone. And honestly, self-repairs that don't stay repaired are the root-cause of people giving up, condemning them, and switching over to alternators (which often can lead to the same frustration on the road as a generator). A professionally repaired generator done by someone in the hobby (NOT A GENERATOR/ALTERNATOR SHOP) will produce a generator which will run for perhaps the rest of your life (they can be that reliable). The advice to contact Brent Mize is good advice (and there are others, too).

Last year I rebuilt my generator (2022). There was no out put and readjusting the third brush was no help.

I removed the generator from the car and connected a battery to the appropriate terminals to see if the generator would motor. The purpose is if it will operate as motor, the generator is functional and repairable.

My issue on not getting current/voltage was the third brush.

https://www.mtfca.com/discus/messages/5 ... 1434487425

Bill.... Thanks for your p.m., I should have written " buy " , not " sell " the generator insulating gaskets........ There are videos on the Model T Ford of America "YOU TUBE" website that do describe rebuilding the generator, with some helpful hints....... In essence I was just referring to the vendors that do sell the gaskets and you could replace those yourself instead of purchasing a rebuilt assembly

Barteldes wrote: ↑

Sat Jun 03, 2023 12:49 pm

1924 Coupe
i wasn't getting any reading on the ammeter so i watched a few videos and set my cut off switch to 6.5 (It was at like 2) and started moving the third brush. (toward the engine) Still nothing shows on the right side of the meter. I do think the meter is working as it shows a negative 1 when i turn on the lights (brights). Is my generator shot? I did try looking at all the connections. I took off the ignition / meter assembly and even tried to clean the gauge a little. Previously i had some trouble with the lights only the dims worked and after messing with them now only the brights work. I have no clue why. and before when only the dims worked the meter didnt move.
im thinking the generator doesnt work. wadda yall think?

Its difficult to provide assistance unless your descriptions are more detailed. You did a fairly good job about what you have done with the cutout & generator but still haven't answered questions about the ammeter & exactly what headlight bulbs you are using.
Unless you have confirmed you have a properly functioning ammeter your attempts to adjust the 3rd brush is pointless This was discussed in your previous discussion entry. In this one you said you "tried to clean the gauge a little" - how ? internally or externally? But that seems to imply you haven't replaced it yet. Having said that, consider this. If you have a bad ammeter that doesn't register a charge does this mean the generator is not working? No!
Here some set up to resolve ammeter & Bright/dim issues
-Ammeter Test is just to verify that the ammeter moves equally in both directions when a load is applied simply by reversing the battery connections.
An LED bulbs may only in a slight movement 1 amp while a filament bulb would do 2 or higher. If you only get movement in one direction then the ammeter is bad. No point in resolving the generator issues till you have a good ammeter.
--
The Bright/Dim tests is to verify if the bulb is equivalent to a dual filament incandescent bulb if its an LED. No need to reverse wires, just take the bulb out and reverse the pins when replacing it. You should see a difference in brightness.
--
Now the issue you have with the headlights only working on either bright or dim but not both - can be a bulb issue or a wiring issue. Th wiring to the headlight biulbs should be in parallel to the terminal block

I have ordered a new ammeter and two kinds of bulbs with dual filaments. The bulbs i have only have one contact at the middle of the stem. the ones i ordered have two contacts. My attempt of cleaning the ammeter was tentative. I cleaned it outside with electrical cleaning spray (for sensors and such) and took off the cover and seeing how delicate it was i got very careful with it. i did spray with an electrical spray. i dont have the can in front of me at the moment to tell you what kind. I sure appreciate all the help you guys are amazing.

Barteldes wrote: ↑

Tue Jun 06, 2023 1:45 pm

The bulbs i have only have one contact at the middle of the stem. the ones i ordered have two contacts.

They're not interchangeable. How many contacts do you have inside of the lamp socket?

There is almost nothing that electrical contact cleaner can do for an ammeter, since there are no real contacts to clean.

Barteldes wrote: ↑

Tue Jun 06, 2023 1:45 pm

I have ordered a new ammeter and two kinds of bulbs with dual filaments. The bulbs i have only have one contact at the middle of the stem. the ones i ordered have two contacts. My attempt of cleaning the ammeter was tentative. I cleaned it outside with electrical cleaning spray (for sensors and such) and took off the cover and seeing how delicate it was i got very careful with it. i did spray with an electrical spray. i dont have the can in front of me at the moment to tell you what kind. I sure appreciate all the help you guys are amazing.

The early sockets for headlights were for a single filament bulb and the later dual filament. Now the base of the dual filament is a BA15D (opposite pins) not to be confused with a BAY15D (offset pins one higher than the other). Now Auto-parts Stores dual filament bulbs (1157) are BAY15D. The BA15D 1156 bulbs are single filament. So be careful what you order. Next not sure what sockets etc you have, the attachment is what all you need for dual filament (or even LED BA15D 6 volt) I have used sockets (limited other parts) for sale if you need

Jerry VanOoteghem wrote: ↑

Tue Jun 06, 2023 2:30 pm

Barteldes wrote: ↑

Tue Jun 06, 2023 1:45 pm

The bulbs i have only have one contact at the middle of the stem. the ones i ordered have two contacts.

They're not interchangeable. How many contacts do you have inside of the lamp socket?

There is almost nothing that electrical contact cleaner can do for an ammeter, since there are no real contacts to clean.

the lamp sockets have two contacts

Barteldes wrote: ↑

Tue Jun 06, 2023 4:51 pm

Jerry VanOoteghem wrote: ↑

Tue Jun 06, 2023 2:30 pm

Barteldes wrote: ↑

Tue Jun 06, 2023 1:45 pm

The bulbs i have only have one contact at the middle of the stem. the ones i ordered have two contacts.

They're not interchangeable. How many contacts do you have inside of the lamp socket?

There is almost nothing that electrical contact cleaner can do for an ammeter, since there are no real contacts to clean.

the lamp sockets have two contacts

Perfect!

Barteldes wrote: ↑

Sat Jun 03, 2023 8:36 pm

following the flivver channel you tube,(generator three part series)

Glad you found the videos helpful. Others here are giving you more nuanced advice, I see. Great! Here is the link if others are interested Ford Model T Generator System: https://www.youtube.com/playlist?list=P ... Wo-GxTmDBD