The Ford Barn

Del in NE Ohio · 10-01-2019, 02:55 PM

Working on A with charging system issues. Has newly rebuilt generator with NuRex solid state cut-out. With motor running, not charge at ammeter, Does, however, show discharge if you turn on lights ( ammeter OK). With motor at idle, I place jumper across cut-out and now have charge of 10 amps. I remove jumper and still +10 amps. Shut of motor, restart and no charge. Re apply jumper and once again +10 amps. Go for a drive and shortly after leaving garage, charge is lost and ammeter falls back to zero. Have tried two new cut-outs which test OK for current flow and direction. I'm kinda lost. any ideas?

Patrick L. · 10-01-2019, 03:52 PM

What type of cut-outs are you using ? Any originals ?

Sounds like the problem is with the cut-outs.

Loosen the fan belt, apply power to the generator and see of it tries to motor. If it does motor, or tries to, that leads me to bad cut-outs.

1931 flamingo · 10-01-2019, 04:56 PM

Call NuRex???
Paul in CT

eagle · 10-01-2019, 06:03 PM

Are you sure thats a solid state cutout ? Sounds like normal operation for a fun projects regulator. Will only charge if battery needs it. However, shorting across a voltage regulator is not a good thing.

Tom Wesenberg · 10-01-2019, 07:10 PM

So, you are using a diode cutout with correct polarity, but the generator looses it's magnetism.
Who rebuilt the generator, and are the pole shoes tight to the body, and what is the air gap from the armature to the pole shoes?
I had an armature that tested good, but someone turned the armature to remove rust, and this made the air gap too great to give good output. It operated similar to what you have going on.

History · 10-02-2019, 07:18 AM

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My generator wouldn't charge so I did what any of us would do, I took it apart. It was filthy inside with dirt and rust. I had a brass wire wheel in a drill and it fit almost perfect inside the housing to clean the plates and I did the same to the armature. I scraped out between the gaps on the small end with something plastic but sharp. Cleaned and lubed the brush holders. Put it back together and learned what the third brush does. I looked for any burnt or black spots and found none. I found it would motor after I cleaned it. It works great now. I know this doesn't help the poster but it may help someone else as they search.

Del in NE Ohio · 10-02-2019, 01:20 PM

UPDATE. Tried 2 solid state (NuRex) and 3 original type mechanical cut-outs. All with same result. No charge unless I placed jumper across cut out. Generator was recent rebuild by reputable rebuilder in NE Ohio. Removed and inspected generator. Found one brush was not contacting commutator at all and the commutator surface was contaminated with a black tar-like mess. Rebuilder gave me another generator. Installed and all is well.

Patrick L. · 10-02-2019, 02:44 PM

Its always nice to hear the results. Glad the 'rebuilder' made it right.

burner31 · 10-03-2019, 10:15 AM

Have you check all three brushes for free movement/contact?

10-01-2019, 02:55 PM	#1
Del in NE Ohio Senior Member Join Date: May 2010 Location: Columbiana,OH Posts: 461	generator not charging _ How come? Working on A with charging system issues. Has newly rebuilt generator with NuRex solid state cut-out. With motor running, not charge at ammeter, Does, however, show discharge if you turn on lights ( ammeter OK). With motor at idle, I place jumper across cut-out and now have charge of 10 amps. I remove jumper and still +10 amps. Shut of motor, restart and no charge. Re apply jumper and once again +10 amps. Go for a drive and shortly after leaving garage, charge is lost and ammeter falls back to zero. Have tried two new cut-outs which test OK for current flow and direction. I'm kinda lost. any ideas?

10-01-2019, 03:52 PM	#2
Patrick L. Senior Member Join Date: May 2010 Location: Largo Florida Posts: 7,225	Re: generator not charging _ How come? What type of cut-outs are you using ? Any originals ? Sounds like the problem is with the cut-outs. Loosen the fan belt, apply power to the generator and see of it tries to motor. If it does motor, or tries to, that leads me to bad cut-outs.

10-01-2019, 04:56 PM	#3
1931 flamingo Senior Member Join Date: May 2010 Location: new britain,ct 06052 Posts: 9,389	Re: generator not charging _ How come? Call NuRex??? Paul in CT

10-01-2019, 06:03 PM	#4
eagle Senior Member Join Date: Aug 2011 Location: Eagle Bend, MN Posts: 2,025	Re: generator not charging _ How come? Are you sure thats a solid state cutout ? Sounds like normal operation for a fun projects regulator. Will only charge if battery needs it. However, shorting across a voltage regulator is not a good thing. __________________ "There are some that can destroy an anvil with a teaspoon and shouldn't be allowed to touch anything resembling a tool."

10-01-2019, 07:10 PM	#5
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: generator not charging _ How come? So, you are using a diode cutout with correct polarity, but the generator looses it's magnetism. Who rebuilt the generator, and are the pole shoes tight to the body, and what is the air gap from the armature to the pole shoes? I had an armature that tested good, but someone turned the armature to remove rust, and this made the air gap too great to give good output. It operated similar to what you have going on.

10-02-2019, 07:18 AM	#6
History Senior Member Join Date: Oct 2017 Location: NC Mountains Posts: 689	Re: generator not charging _ How come? Sponsored Links (Register now to hide all advertisements) My generator wouldn't charge so I did what any of us would do, I took it apart. It was filthy inside with dirt and rust. I had a brass wire wheel in a drill and it fit almost perfect inside the housing to clean the plates and I did the same to the armature. I scraped out between the gaps on the small end with something plastic but sharp. Cleaned and lubed the brush holders. Put it back together and learned what the third brush does. I looked for any burnt or black spots and found none. I found it would motor after I cleaned it. It works great now. I know this doesn't help the poster but it may help someone else as they search.

10-02-2019, 01:20 PM	#7
Del in NE Ohio Senior Member Join Date: May 2010 Location: Columbiana,OH Posts: 461	Re: generator not charging _ How come? UPDATE. Tried 2 solid state (NuRex) and 3 original type mechanical cut-outs. All with same result. No charge unless I placed jumper across cut out. Generator was recent rebuild by reputable rebuilder in NE Ohio. Removed and inspected generator. Found one brush was not contacting commutator at all and the commutator surface was contaminated with a black tar-like mess. Rebuilder gave me another generator. Installed and all is well.

10-02-2019, 02:44 PM	#8
Patrick L. Senior Member Join Date: May 2010 Location: Largo Florida Posts: 7,225	Re: generator not charging _ How come? Its always nice to hear the results. Glad the 'rebuilder' made it right.

10-03-2019, 10:15 AM	#9
burner31 Senior Member Join Date: Dec 2014 Location: Shawnee, Ok Posts: 3,471	Re: generator not charging _ How come? Have you check all three brushes for free movement/contact? __________________ Keith Shawnee OK '31 SW 160-B

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