MTFCA Forum

I've owned my T for a couple months. In that time the generator hasn't shown a charge. Since I've been working through other issues with it I haven't spent much time trying to figure out what is going on with it. I did jump across the cut out switch per the service manual to see if anything changed, but nothing did. Yesterday I jumped across the cut out switch again and it immediately showed a charge. After I removed the jumper it continued to charge. I shut it off and checked for voltage in the generator side of the cut out and there was nothing. I fired it back up again and it was charging.

It was showing about 10 amps on the gauge so I figured that I'd go for a drive to see what it read at the speed I usually drive. After I we got in to go it didn't charge. I jumped across the cut out again and still nothing. We went ahead and drove around about 20 miles & it never did show a charge. After we got home I started it back up and put the jumper on at it started charging again, so I pulled the jumper off and drove up the road and back with the lights on to see if it still worked. It continued to charge but was putting out more amps than I've read I should be.

This morning I polished the armature and it continued to charge, but at about 9 amps. I decided to adjust the 3rd brush to see if I could bring it down a little. As I bumped it toward the engine it kept dropping the amperage on the ammeter. At one point it was too low so I moved it away from the engine. Rather than increase the amps it dropped it further. Now no matter where I put the 3rd brush I can only get a maximum of about .5 volts on the generator terminal.

Is it time to send it away for professional help or is there something else I could try?

From all the information you supplied, it sounds like a burnt out generator and a questionable cut out. Sounds like Ron Patterson could be a great help to you.

Boaski, You may not want to hear this (and I'm opening myself up again to public scorn) but after 5 years of dealing with generator problems and the mysteries therein, I comitted an unforgivable sin. I replaced my generator with an alternator. If you are a staunch purist please ignor my response to your post. However, if you are tired of dealing with your uncoooperative, unreliable, expensive, unpredicatble, seemingly unfixable Model T generator you may want to consider replacing it with an alternator. Just sayin'

Gracie's dad..... Scorn you say , ... scorn....?? Well, I'm in the same boat as you. I did replace mine with an alternator many years ago and have not had any problems.

Are either of you guys using the 6 volt alternator from Langs?

https://www.modeltford.com/item/5119ALT6B.aspx

Todd . .. I bought my alternator years ago from the original proprietor of Becker Alternator, that was located in Ohio. Sadly, he is no longer with us and his family has closed the business. If you can find someone that is selling a Becker alternator, I'm sure you will be satisfied with the results. I have not had any problems in all these years. You can find contact information for Ron Patterson right here on the forum as you wish to fix your generator.

When you reset the third brush you have most likely broke the insulator and the generator is grounded.
This is a common failure. Since you’re having to jump across the cutout two things could be at play here.
First the cutout may be toast or you have an armature issue. The armature could be partially grounded and not allowing the build up to begin during start up of the generation cycle. Jumping the cutout allows battery voltage to energize the fields to force that process since you most likely have a partial short in the armature.
We rebuild generators and they will be as good as new.
Coildoctor.com
I hope this helps,
Brent

Your generator should INCREASE charge as you rotate the 3rd brush closer to the motor. That tells me the brush holder is out of adjustment.(4 screws)
I would do the Ron Patterson "low amp" adjustment procedure. Set the 3rd brush about 1/4 travel. Rotate the brush holder to minimum output. Lock the 4 screws. Reset generator output(3rd brush) for a desired 4-6 amps.

Keeping in mind your cutout is working intermittent. I believe you do have a cutout issue.
You can remove the cover & watch the points. Manually close if needed for your generator adjustments.
Also check those contact points for burning. They may need dressing. Dont forget to remove or shut off the power on the cutout output terminal before filing the points.

Anyway, you have nothing to lose before sending the gen out for rebuild.

In its present state, ground out the generator output terminal & remove the cutout terminal power. (Tape up the wire terminal to not ground the battery.)If you are going to drive anymore.

You can still drive on a full battery for several days.(using your starter sparingly or hand cranking.
Grounding the generator will prevent any further damage to it.

Surrendering to an alternator would not be a choice for me, personally. I like my T's the way God & Henry intended
No scorn intended.

Brent is giving good advice, send it in for rebuild.

I've had good results by picking up used generators from swap meets. I swap parts around until I get one to work. I guess I'm a cheapskate. If the generator goes out o a tour, I just ground the output and use the crank and magneto the rest of the tour. There have been more cars on the trouble truck with a bad alternator, than almost any other problem. Most people on alternator run their cars on 12 volts instead of on magneto, and so when the alternator goes out they stop running. A couple problems with alternators is they were not originally meant to be bolted up to the engine and run from a gear. They remove the original pulley and install the gear. The pulley has a fan in it which keeps the alternator cool while driving, whereas when the engine heats up, there is no way to keep the alternator cool and also, many times the gear comes off.
Anyway, there are some modifications to a T which are improvements, but many, including the alternator are not as good as the original system.
Norm

Cheapskate here as well and have also pieces together a generator from several. On the speedster there is an alternator that works great when it works. Right now it isn't working so either it's dead, gear is off or something. It's on my list right after the Buick is operational. Until then just charge the battery. The simplest with a T is to remove the cutout and simply put in a diode. As the generator on the Buick drives the dist I will be going the gen/diode route as that works for 12 or 6v.

It would be very helpful also to look into a website.....www.modeltstarters.com. .... Jeff is very experienced with starters, generators, cutouts, and voltage regulators.

Yes, my alternator came from Lang's. It took 15 minutes to do the swap, complete with drive gear, has built in regulator, no messing with cores, costs less than a generator rebuild, painted black and works perfectly. My life is now simple.

Ron Patterson doesn't do generators anymore - he limits his services to the repair of coils now.

Thank you all for the responses.

I have a follow up question:

A few mentioned that I have a cut out switch problem. I guess I don't understand that one & I probably didn't explain properly what I observed. There has not been a single instance that the generator was producing voltage that the cut out did not close, and there has never been a time that the generator was NOT producing voltage that the cut out switch did not open. The only reason I jumped around the cut out was to try to get the generator to produce some voltage as is instructed in the service manual.

One of my disadvantages is I'm new to the Model T hobby, so I don't have extra "T stuff" laying around. With out extra stuff to try I'm pretty limited on just trying a different doodad when I suspect a problem. My main hobby is vintage snowmobiles & I have 40 years worth of accumulated stuff laying around for them & every now and then something that I've had on the shelf for a decade or so comes in hand. My wife thinks I have a problem, but I think differently....

Gracie'sDad wrote: ↑

Mon Sep 04, 2023 6:30 pm

Yes, my alternator came from Lang's. It took 15 minutes to do the swap, complete with drive gear, has built in regulator, no messing with cores, costs less than a generator rebuild, painted black and works perfectly. My life is now simple.

DITTO. I bit the "purist bullet" and put one on my Fordor after fighting with the generator umpteen times and NO regrets!

I have always stuck with what came with the car and has always worked for me. I see this in the Model A community a lot. Nothing wrong with it, just my view.

Ten years ago, I sent my generator to Brent Mize and he did a great job on it. I highly recommend his work. Since you are new to the hobby and are not sure what the problem is, I would recommend you send off the generator to Brent to do a diagnostics check on it to determine exactly what is wrong. Send your cutout also. After he does the diagnostic check, he will get back to you and have an answer as to exactly what you need and how much it will cost. Jim Patrick.

That little adjusting nut have got a lot of people I know in trouble.

If you tighten it too much you will break the insulation on the brush assembly and have no generator output.

If you leave it too loose, the armature will move it to a higher output level and burn out the generator.

It is best to decide that is not your problem and leave it for the experts, like Brent!

It looks like Brent Mize is only about an hour away from me. I'm going to try to limp the car a long a little while before I pull it as we're heading towards winter anyhow & I want to be able to putt around while the weather is decent.

Brent does not necessarily rebuild your generator, he may sell you an already rebuilt generator and take yours as a core.

Boaski .... Good luck on your decisions,