Generator putting out too much power

HalcyonDays

HalcyonDays

Senior Member
I have a 1931 Generator that I cannot seem to adjust below 20 amps. Rotating the third brush I can adjust between 20 amps to 30 amps depending on which extreme I position the brush. I cannot get it below 20 amps. It should be adjusted to 8 amps. Has anyone run into this problem before? Any thoughts would be great.
 
Are you sure your third brush is traveling all the way?
Full range of motion (both ways) for the brush.

Just off the top of my head
 
What are you using to measure your charge current? The dash meter (questionable accuracy) or a known accurate ammeter? I have always used an external ammeter of known accuracy. I have always distrusted the accuracy of my dash meter.
Just wondering.
 
Are you sure the field and output wires are connected to the correct brushes?

I've had to repair two cooked generators that "generator shops" had reversed those 2 wires.
 
What is the battery voltage compared to the generator voltage, when I ran a 6 volt generator with a 6 volt battery it made 8 amps, when I hooked the same generator to a 12 volt battery it made over 25 amps and got hot
 
Thank you for the replies. I am sure the third brush was traveling its full range, I was using an external ammeter, the tests were performed while it was attached to a battery and on the car and it is a six volt battery. The car is new to me,was partially disassembled when I purchased and had not been started in many years, possibly thirty or more. Looking inside the generator the brushes look new, although the repair history has been lost. The reversal of wires seems like a real possibility and I will check that. Thanks again for all the replies any other thoughts are welcome.
 
My coupe came with a generator from a later car, has two wires coming out. I couldn't get less than 12 amps. It wasn't in very good shape anyway, so I replaced it with an alternator.
 
HalcyonDays said:
TThe reversal of wires seems like a real possibility and I will check that. Thanks again for all the replies any other thoughts are welcome.
Click to expand...

Yeah. Check the polarity. If it was in storage and not used and if you bought a new battery and connected it with negative to ground like any other car, you will be in trouble. Positive goes to ground on the model A unless it has been rewired/converted.
 
A couple of years ago I rebuilt a couple of A generators,on both of them ,8 amps was as low as I could set them. I added Tom Wesenberg voltage regulator and all is well. I am convinced the modern battery chemistry has something to do with this. What say you folks?
 
Update. The field and output wires were connected to the wrong brushes. Once this was corrected the generator is now running fine. Thank you all for your help.
 
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