Generator problems

M

marrowe

New member
Hi all, I'm having trouble diagnosing the reason my 1930 generator won't put out any charge.

I have opened up the cutout, the points aren't stuck but nor will they close when the generator is running. I'm planning on replacing the cutout with a new electronic unit anyway. Is there a way of testing the function of the original style cutout?

I then checked whether the generator was producing any current using a test lamp to the output wire, nothing.

I then tried motoring the generator, which worked slowly.

The carbon brushes all seem to have plenty of life left in them

I'm not sure what to check next, any ideas greatly appreciated thanks
 
Mine wouldn't charge so I took it apart and cleaned everything, put it back together and it worked. Mine was filthy inside, I used a round wire brush in a drill to clean the inside of the pads, carefully. It charges great now. If yours motors slowly cleaning might help. It's in the les Andrews book how to do this. It's not a big deal to do.

Good luck and let us know what it turns out to be.
 
If it motored then its probably ok.

Try polarizing it. Jump the cutout terminals of a nano second . But motoring it should have done that.

It appears there is probably a cut0out issue. They can be adjusted. Originals seem to be the better than repro's.

Make sure the ammeter is working correctly. Turn lights on and make sure it shows a discharge.
 
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Sometimes you get lucky by just replacing the wear parts with a generator but it's a crap shoot. If the field is bad or the armature then you are right back where you started. Find a good electrical shop or find a local club and check to see if a member has a growler set to test the armature. The rest can be done with a multimeter. The field pole shoes need to be flashed to get polarity and magnetic gauss to a point where it will generate enough current to close the cut out & bring the generator on line. You also have to make sure your battery is in good condition. A three brush generator depends on a good battery to make it function like it should. It takes a bit of current from the generator to function a cut out. A person can test them if they have an adjustable power source. The cut out can also be bypassed with a test lead if your careful. An on off switch could be substituted for a cut out but you have to remember to turn it off when the engine is stopped or it will ruin the battery and the generator.
 
I like to adjust the cutout to close at 6 to 7 volts.
A car battery connected to the cutout case and input will close at this voltage, but many won't close until a higher voltage is reached.
 
If the generator is not putting out anything then messing with the cutout is a waste of time at this point. If you are unable do the work then you need to find a shop that can do Model A 3 brush generators or get a rebuilt one. Other way is to buy one of the repair books that cover generator repair.
 
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redmodelt said:
If the generator is not putting out anything then messing with the cutout is a waste of time at this point. If you are unable do the work then you need to find a shop that can do Model A 3 brush generators or get a rebuilt one. Other way is to buy one of the repair books that cover generator repair.
Click to expand...



If you need one quick, Berts has rebuilt generators. Additional $35 core charge. Make sure to ask if they are backlogged, and how long if they are backlogged.


If not on backlog they ship immediately, and you send in yours to get the core refund.
https://modelastore.com/index.php?route=product/search&search=generator&category_id=0


Lots of others want you to send in your core before shipping out a rebuilt.


With Berts you can pay the core charge, keep yours, and try rebuilding it at your leisure.
 
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