Original generator: Charging rate changes when hot?

[bikemaniac]

Hi,

I tried to play with the generator charging rate of my model A and have noticed the following: When the engine is cold and I adjust the brush to a charging rate of 4 Amps, the charging rate will rise to about 8 Amps once I have driven the car a bit. Is that normal?

Lucas

 

[Tom Wesenberg]

No, it's not normal. I wonder if you have a poor connection, such as where the two field coils are twisted and soldered together.
Is the commutator undercut about .010" between the segments?
Are all 3 brush springs in good condition?
How old is the battery?

 

[bikemaniac]

I rebuilt the generator last year and ensured sufficient undercuts. Brush springs are OK.

But the battery is bad. Very bad. Bought it last year and it is already damaged: I can charge it, but it is depleted very quickly: I can make 1 start with the starter and thats it. But there is plenty of power for the ignition and lights.

 

[Tom Wesenberg]

I would try a good battery before looking for generator problems.

 

[ian Simpson]

I would try a good battery before looking for generator problems.

and I would look to cleaning up grounds also.

 

[Mike V. Florida]

I would try a good battery before looking for generator problems.

The battery is the "regulator" in the model A system. This is why the generator will still charge 8 and even 12 volt batteries. That also the reason why Tom says to start with a good battery.

 

[H. L. Chauvin]

Could it be that you "charge" the battery when the engine is "cold" ........ when the battery is "charged", you can use the starter only once ..... then the generator charges at 4 amps with a "charged" battery ...... next, as the battery slowly dies the generator charges up to 8 amps and supplies power for ignition and lights as the engine gets "warm" ..... then when the engine stops and the generator is not turning, the battery is dead and cannot turn the starter.

As you mentioned: "But the battery is bad. Very bad." and,

"I can charge it, but it is depleted very quickly."
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Sounds something like, what does one do with bad apples, bad sweet potatoes, bad eye glasses, bad hearing aids, and a bad radio?

 

[Mitch//pa]

I rebuilt the generator last year and ensured sufficient undercuts. Brush springs are OK.

But the battery is bad. Very bad. Bought it last year and it is already damaged: I can charge it, but it is depleted very quickly: I can make 1 start with the starter and thats it. But there is plenty of power for the ignition and lights.

You most likely answered your own question as to what the problem is...