The Ford Barn

cp5491r · 10-31-2024, 07:25 AM

I'm a novice.
Original 6 volt model A system with generator.
The ampmeter won't show a charge when running/driving the car. It does show discharge when I use the horn. Any likely causes? I replaced the cutout.
Thanks!

chap52 · 10-31-2024, 07:50 AM

Original style generator? If so have you adjusted the generator output by moving the adjustable brushes? Chap

rotorwrench · 10-31-2024, 09:18 AM

The modern reproduction ammeters are not as sensitive nor as accurate but they will function adequately. I recommend that folks not use the plastic covered finger nuts and just use regular nuts with lock washers. A loose connection will do damage to the meter.

As was mentioned previously, the 3-brush generator may need the 3rd brush adjusted to a happy place for best function. Ford recommended that an accurate ammeter be placed in the output line when adjusting the amperage output. Some folks adjust for daytime operation and some for night time operation. It depends on how much night driving is done. A person should run with lights on all the time for high output or the battery may be overcharged.

If the generator isn't functioning then it won't show a charge. A person has to make sure it's working so an adjustment of the brush is a place to start. Make sure all connections between the battery and generator are clean and tight. The battery is what regulates the voltage so this is critical.

cp5491r · 10-31-2024, 09:37 AM

Thanks for those great suggestions. It is an original style generator and the car only gets driven about once a year (I'm bad) so the connections is also a great suggestion. Thanks!

Will N · 10-31-2024, 10:31 AM

If the car has sat for a long time the field coils may have lost their magnetism, and you can try to polarize the generator by touching a jumper wire to both sides of the cutout for a second. This will send current through the field coils which will re-establish the latent magnetism in the coil cores.

ndnchf · 10-31-2024, 02:09 PM

Sponsored Links (Register now to hide all advertisements)

Check out my video in how to adjust the 3rd brush.
https://youtu.be/PL94VX3GIq8?si=evEiDv5hGv7JwIbV

Doug Linden · 10-31-2024, 08:42 PM

Could be that the cutout is not working. With the engine running put a jumper wire across the two connections on the cutout and check the ammeter to see if it shows a charge.

shew01 · 11-02-2024, 05:55 AM

Quote:

Originally Posted by ndnchf

Check out my video in how to adjust the 3rd brush.
https://youtu.be/PL94VX3GIq8?si=evEiDv5hGv7JwIbV

Thanks for the link. I’ve read about this before, but it makes better sense now.

Sent from my iPhone using Tapatalk

10-31-2024, 07:25 AM	#1
cp5491r Senior Member Join Date: Jun 2012 Location: Waukee, Iowa Posts: 109	Ampmeter not charging I'm a novice. Original 6 volt model A system with generator. The ampmeter won't show a charge when running/driving the car. It does show discharge when I use the horn. Any likely causes? I replaced the cutout. Thanks!

10-31-2024, 07:50 AM	#2
chap52 Senior Member Join Date: Jun 2013 Location: Marana Arizona Posts: 1,829	Re: Ampmeter not charging Original style generator? If so have you adjusted the generator output by moving the adjustable brushes? Chap

10-31-2024, 09:18 AM	#3
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 17,410	Re: Ampmeter not charging The modern reproduction ammeters are not as sensitive nor as accurate but they will function adequately. I recommend that folks not use the plastic covered finger nuts and just use regular nuts with lock washers. A loose connection will do damage to the meter. As was mentioned previously, the 3-brush generator may need the 3rd brush adjusted to a happy place for best function. Ford recommended that an accurate ammeter be placed in the output line when adjusting the amperage output. Some folks adjust for daytime operation and some for night time operation. It depends on how much night driving is done. A person should run with lights on all the time for high output or the battery may be overcharged. If the generator isn't functioning then it won't show a charge. A person has to make sure it's working so an adjustment of the brush is a place to start. Make sure all connections between the battery and generator are clean and tight. The battery is what regulates the voltage so this is critical.

10-31-2024, 09:37 AM	#4
cp5491r Senior Member Join Date: Jun 2012 Location: Waukee, Iowa Posts: 109	Re: Ampmeter not charging Thanks for those great suggestions. It is an original style generator and the car only gets driven about once a year (I'm bad) so the connections is also a great suggestion. Thanks!

10-31-2024, 10:31 AM	#5
Will N Senior Member Join Date: Jul 2010 Location: Pennsylvania Posts: 1,251	Re: Ampmeter not charging If the car has sat for a long time the field coils may have lost their magnetism, and you can try to polarize the generator by touching a jumper wire to both sides of the cutout for a second. This will send current through the field coils which will re-establish the latent magnetism in the coil cores.

10-31-2024, 02:09 PM	#6
ndnchf Senior Member Join Date: May 2012 Location: Fredericksburg, Virginia Posts: 1,088	Re: Ampmeter not charging Sponsored Links (Register now to hide all advertisements) Check out my video in how to adjust the 3rd brush. https://youtu.be/PL94VX3GIq8?si=evEiDv5hGv7JwIbV

10-31-2024, 08:42 PM	#7
Doug Linden Senior Member Join Date: May 2010 Location: Massachusetts Posts: 292	Re: Ampmeter not charging Could be that the cutout is not working. With the engine running put a jumper wire across the two connections on the cutout and check the ammeter to see if it shows a charge.