Hi, Roy from Maryland here. I am de-mothballing a '26 pickup and have a question about generator output.
I put a new battery in (DEKA 6V), and I observed the amp meter reads around 30 Amps running on the road. When I turn the lights on to lower the battery charge, the ammeter goes to near "0". I will check all wires for shorts, and I haven't yet attempted to set the 3rd brush, but going to "0" seems extreme, not a 3rd brush problem. If it's putting out 30 amps, and the lights draw 8 or 10(?), I still shouldn't be at "0" just turning on the lights?
Is there something I should look for in the generator that could be causing this?
The lites take 10 to 12 amperes, so if the ammeter reads zero with the lites on, I would suspect he ammeter is reading high. If you or a friend have an ammeter, connect it between the cutout and the lead to the terminal block, this will allow you to check the actual current from the generator.
1926 ammeters are not accurate. A word of caution, if you run the generator at a high rate of output for a long time, you can ruin the generator. I would suspect that the generator is in original condition. So when you adjust the 3rd brush, be careful in that this motion can damage hardened insulation inside the generator. If you intend to use the car, and you should, you should set the generator 3rd brush, and then if trouble comes up repair the brush rigging on the generator. I'd do what Tony says, get a good ammeter and set the third brush so that there is about 3 or 4 ampere charge when the engine is idling. Another good idea would be to get the MTFCA generator book. You can find it in the MTFCA store. Good luck. Mike
I agree with Tony. If you are running a stock T generator with a cutout, 30 amps charge is excessive. It would cause the generator to get hot and burn out. The charge should be around 5 amps and when you turn on the lights it would show a small discharge. If you do a lot of driving with the lights on, you should adjust the third brush to read around 0 amps with the lights on. But if most of your driving is with lights off just set for 5 amps and the small amount of driving with lights on should not be a problem.
Your T might have a voltage regulator in which case it could show a greater charge right after starting the engine but as soon as the battery reaches full charge the rate would be at or just above 0.
I think Tony is right. Some of the ammeters on the cars are not accurate and at best will just let you know it is either 0, charging, or discharging.
I disagree with what Mike said to adjust the generator to 3-4 amps when the engine is idling. The generator will not put out a charge until the engine is at a fast idle. So set the idle up to about 1000 rpm when you check the output. That would be about the speed the engine would run in high gear at 20-25 mph.
That's the MTFCA book on The Electrical System. It covers all the electrical stuff. As an electronic dummy who gets a case of MEGO when people get into electrical theory and start discussing how many microfoonads of impudence it takes to fleem the drelb, I find the practical advice in the book very helpful.
Thanks everyone. I think I will hook up an ammeter to check the one on the dash.
I work on Model T electrical systems every day and know the generator workings well.
If you would like to work with me off line on your generator trouble give me a call 859-881-1677 11AM to 4PM EST.
Ron the Coilman
Steve - I'm exactly where you are in regards to anything electric! In fact, no doubt a bit more "electrically challenged" than you. I have however, made one interesting (but useless) observation in several threads similar to this one:
Apparently, you have to have some combination of gray hair, or thin hair, or no hair, to know that an ammeter is an ammeter,...not an amp gage, or an amp meter, or whatever!
(......but then perhaps I have a few too many microfoonads of impudence, huh?)
Norm, you are probably right, maybe 3-4 amps is a little high, but adjusting the 3rd brush with old insulators can be difficult, especially if the insulator is cracked. The point is at idle the charge should be low and this is when you have a battery that is up to snuff, at 1.265- 1.275 specific gravity. If you set the charge low on a partially discharged battery, you'll have trouble getting that battery to full charge. My 2¢. Mike
If you haven't done so yet, I recommend giving Ron Patterson a call at the number he provided above. He'll give you some great advice.
NOT meant to slight the others here, who have given good and valuable advice as well!
If you put your hand on the generator and it is hot, its a pretty good sign that the output is set too high.
Roy - take Ron Patterson up on his offer.