Rebuilt generator, major discharge
- Thread starter Desert Toad
- Start date
Desert Toad
Member
Yes! That helps it all make sense. I switched the two wires on the brushes, and no more over charging. 
The charge rate is nice and steady, no bouncing needle like before the rebuild. Except now I'm back to a discharge while running the headlights. And I know from experience that makes for a rough running engine. We'll save that problem for another day.
A big thanks to ALL of you for sticking with me to get things sorted out.
Looks like Frank will get out of the barn after all this weekend.
The charge rate is nice and steady, no bouncing needle like before the rebuild. Except now I'm back to a discharge while running the headlights. And I know from experience that makes for a rough running engine. We'll save that problem for another day.
A big thanks to ALL of you for sticking with me to get things sorted out.
Looks like Frank will get out of the barn after all this weekend.
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Mike V. Florida
Well-known member
Yes! That helps it all make sense. I switched the two wires on the brushes, and no more over charging.
The charge rate is nice and steady, no bouncing needle like before the rebuild. Except now I'm back to a discharge while running the headlights. And I know from experience that makes for a rough running engine. We'll save that problem for another day.
A big thanks to ALL of you for sticking with me to get things sorted out.
Looks like Frank will get out of the barn after all this weekend.
That's normal unless you are going to be griving for several hours with the headlights on, the discharge won't hurt anything.
Desert Toad
Member
Perhaps now that the generator is working correctly now, I can run with the lights on. Before, after just a few minutes, the engine would run rough and lose power.
Tom Wesenberg
Well-known member
I would adjust the third brush (adjustable brush) for about a 3 amp output, and not run with the lights on during the day. If you have more amps output, you will be adding water to the battery more often, and ovecharging the battery, unless you do a lot of starts and short drives.
On the post Model A generators the adjustable brush holder is held in place by 2 spring clips, which are riveted to the end plate, rather than spring clips that are screwed, as on the Model A end plate. Here's 3 pictures showing the electronic voltage regulator I make to install on the adjustable brush holder. This way you don't have to worry about adjusting the brush for the correct charge.
With you battery fully charged and the engine off, how many amps discharge does your ammeter show when you turn on the headlights?
Some people put in high amp draw bulbs and they may require more amps to run then the generator can safely produce. The common long generator can safely put out about 12 amps continuous, and the generator with the cooling holes, as pictured here, can safely put out a few more. Ideally you want the battery to be kept charged, but not overcharged, and that's why an EVR is a good thing. Also when the generator isn't putting out too many amps, it's less drag on the V belt and engine.
I like to keep the Model A all stock and original, but there are a few things that will help improve the car. An EVR helps to prolong battery life, a filter in the gas tank helps reliability by prevent junk from getting into the carb jets, a higher speed rear end (or overdrive) helps lower engine RPM and increase speed for those who like to drive over 45.
On the post Model A generators the adjustable brush holder is held in place by 2 spring clips, which are riveted to the end plate, rather than spring clips that are screwed, as on the Model A end plate. Here's 3 pictures showing the electronic voltage regulator I make to install on the adjustable brush holder. This way you don't have to worry about adjusting the brush for the correct charge.
With you battery fully charged and the engine off, how many amps discharge does your ammeter show when you turn on the headlights?
Some people put in high amp draw bulbs and they may require more amps to run then the generator can safely produce. The common long generator can safely put out about 12 amps continuous, and the generator with the cooling holes, as pictured here, can safely put out a few more. Ideally you want the battery to be kept charged, but not overcharged, and that's why an EVR is a good thing. Also when the generator isn't putting out too many amps, it's less drag on the V belt and engine.I like to keep the Model A all stock and original, but there are a few things that will help improve the car. An EVR helps to prolong battery life, a filter in the gas tank helps reliability by prevent junk from getting into the carb jets, a higher speed rear end (or overdrive) helps lower engine RPM and increase speed for those who like to drive over 45.
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Purdy Swoft
Well-known member
I hope that all is good. I figured I had better post again. Remember that I said if after adjusting the third brush, if you didn't see a difference in the chargeing rate that the brush wires were reversed. I should have pointed out that the generator will motor and charge even if the brush wires are reversed. The thing is if the wires are crossed, adjusting the third brush will have no effect on the charging rate and the field coils will burn out quickly. I hope that you now understand how to adjust the third brush and tested before reversing the wires. It is normal to show a discharge with the lights on. The only way that I can see this causeing the engine to run rough and lose power would be if the battery was dead and it was trying to run off the generator.