The Ford Barn

TraVeler · 08-11-2023, 08:49 PM

I have 31 sedan that I inherited from my grandfather and the ammeter will go from pegged discharge when it starts to pegged charging then the fuse would blow when I go to rev it up to pull out. So I put a 30 amp breaker on it same scenario pegs it trips the breaker then the car shuts off. I've used the search function but can't find anyone with the same scenario. There is a condenser in the distributor and I've tried to get the timing down with the nurex wrench. Timing Definately not near where the woody idles but it has its own set of problems. I put new plugs in it and it backfires as well. There is a 6 volt alternator as well

Gary WA · 08-11-2023, 11:05 PM

Need to excite the alternator!?

nkaminar · 08-12-2023, 06:25 AM

It seems that there may be something wrong with the alternator. Try taking the wire off the alternator and starting the car to see if you get the same issue. If the problem goes away with the alternator disconnected, you can take it to an alternator shop (if you can find one) to have it looked at. Or get another alternator.

It may be a 12 volt alternator on a 6 volt car.

It may be a fault with the wiring like a bad ground or loose connection somewhere. Or there may be a short somewhere. If the problem persists with the alternator disconnected then look for a short. There may be a short in the horn or somewhere else. Try disconnecting things one at a time to see if you can isolate the cause.

TraVeler · 08-12-2023, 06:35 AM

thanks all Nkaminar I'm in Western nc too down in Polk.
Does anyone stock a 6 volt alternator like oreilly advanced autozone napa?

Jim/GA · 08-12-2023, 07:29 AM

Quote:

Originally Posted by TraVeler

thanks all Nkaminar I'm in Western nc too down in Polk.
Does anyone stock a 6 volt alternator like oreilly advanced autozone napa?

Regular auto parts stores do not stock 6 volt positive ground alternators. You will have to get it from a Model A parts supplier of your choice. But don't replace it until you confirm it is defective.

I am about 2 hours west of you, if you are in Polk County NC. We should get together.

It sounds like this is your first Model A. I would be glad to travel over there to help you out, if you want. Some basic electric system troubleshooting will pin down the problem very quickly.

Dick M · 08-12-2023, 10:37 AM

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Jim, that's what the Model A hobby is all about. You are willing to travel two hours to help out a newbie. Congrats to you!!!

TraVeler · 08-12-2023, 10:04 PM

I could use the help. Im overwhelmed right now trying to keep them running and i have one more to get out of the weather. I cant get that one(coupe) to start at all. It'll turn over just wont run. Ive got spark at the points. These things sat for 2 or 3 years without moving. I drained the gas out of the tanks but not the carbs. Anyways back to this one that started the thread. The sedan i disconnected the alternator and the ammeter just showed a slight discharge. The number on alternator says 12v negative. Is there a way to test the output voltage of the alternator?

TraVeler · 08-12-2023, 10:09 PM

Here is part number of alternator. Maybe the problem is this car has been converted to 12v?

TraVeler · 08-12-2023, 10:10 PM

1102394 37a

Jim/GA · 08-12-2023, 11:52 PM

Quote:

Originally Posted by TraVeler

I could use the help. Im overwhelmed right now trying to keep them running and i have one more to get out of the weather. I cant get that one(coupe) to start at all. It'll turn over just wont run. Ive got spark at the points. These things sat for 2 or 3 years without moving. I drained the gas out of the tanks but not the carbs. Anyways back to this one that started the thread. The sedan i disconnected the alternator and the ammeter just showed a slight discharge. The number on alternator says 12v negative. Is there a way to test the output voltage of the alternator?

An auto parts store, like O'Reilley or AutoZone, can test a 12 volt neg. ground alternator for you. They don't know anything about the 6 volt pos. ground variety, but this 12 volt neg. is pretty standard on modern cars for a long time now.

You need to get the goop from old, stale gas out of the carbs. Remove the carbs, spray the jets with carb cleaner followed by compressed air and put them back on the engine. Original Zenith carbs are held together by only 1 bolt; easy to take apart and put back together.

rotorwrench · 08-13-2023, 12:46 AM

The OP has a major short to ground. That's what burns fuses. The fuse protects the rest of the circuit. The alternator may or may not be involved but something inside would likely be burned melted or damaged enough to create a dead short. Inspect the charging circuit from stem to stern. It could be anywhere in system portions that are not switched. Lights, horn, and electric wiper are isolated if not switched on. Ignition has to be on to run but a short there won't let it run.

nkaminar · 08-13-2023, 06:27 AM

I cannot travel to you to help right now but I posted what I did to get a car running that had sat outside for 5 years. See https://www.fordbarn.com/forum/showthread.php?t=329463

You have a short somewhere. Disconnect all the wiring and use your multi meter to find the short.

Google the alternator part number to learn if it is 12 V or 6 V. What voltage battery is installed? The 6 volt battery will have 3 caps on top for filling with distilled water. The 12 volt battery will have 2 caps that fill 3 cells each for a total of 6 cells.

Rob Doe · 08-13-2023, 08:09 AM

Which battery post is grounded to the frame??

Badpuppy · 08-13-2023, 08:09 AM

All 6V alternators are converted from 12V, and the case stamping isn't changed. The part number is rather meaningless since it is different for the make/model it was originally installed in.

You need to identify what type system you have, starting with the battery.

eagle · 08-13-2023, 08:42 AM

One thing to remember, the Model A is originally POSITIVE ground. If you dropped a battery in, not knowing that, it would definitely create some havoc. As said above, some alternators have been converted to 6V positive ground so looking at the markings isn't really going to tell you much. Most coils will have a polarity marking on them, usually a + on one side of the primary. If the + is going to the distributor then than is an indicator that it is still positive ground. For sure disconnect the alternator until you figure it out. If you bring the alternator to a competent shop they can tell you if it has been converted. By the way, once you figure this out, DOCUMENT it, put a tag on the alternator and somewhere else on the car. This happens SO often, people make "improvements" to the car and leave no documentation for the next guy. Hydraulic break conversions are the worst for this. Also download a wiring diagram, use the search function here on Fordbarn, they have been posted many times. Good Luck!

nkaminar · 08-13-2023, 09:34 AM

The stock electrical system is here in detail. https://www.mafca.com/downloads/Semi...ex%20Janke.pdf

It is a good resource but your electrical system may have been changed. Common changes are the ignition switch wiring and conversion to an alternator.

Charlie Stephens · 08-13-2023, 01:29 PM

Be careful you don't burn out the ammeter. Original ones are hard to find. If it goes to 30 amp it is a replacement already.

Charie Stephens

TraVeler · 08-13-2023, 06:51 PM

The position cable is on the negative battery post
the ground cable is on the positive post

The ammeter is a 20amp one

How many grounds are there?I'll check the schematic

I'm pretty sure its still a 6 volt system all the batteries have been
6 volts

TraVeler · 08-13-2023, 06:54 PM

Ground cable is attached to trans bolt. I wirewheeled it this am to make sure ground didn't have paint.

Badpuppy · 08-14-2023, 08:02 AM

Check grounding between alternator and battery post. Lack of common reference can lead to high voltage between them. Run AWG #12 between alt. case and battery ground post if necessary.

On a similar note, since battery ground has been moved to the bell housing, you also need a connection between ground post and frame (at least #12) for lights and horn.

08-11-2023, 11:05 PM	#2
Gary WA Senior Member Join Date: May 2010 Location: Clinton,WA/Whidbey Island Posts: 4,105	Re: Hello All Been lurkin for a few week ? about ammeter and alternator Need to excite the alternator!? __________________ www.whidbeymodelaclub.com

08-12-2023, 06:25 AM	#3
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 3,901	Re: Hello All Been lurkin for a few week ? about ammeter and alternator It seems that there may be something wrong with the alternator. Try taking the wire off the alternator and starting the car to see if you get the same issue. If the problem goes away with the alternator disconnected, you can take it to an alternator shop (if you can find one) to have it looked at. Or get another alternator. It may be a 12 volt alternator on a 6 volt car. It may be a fault with the wiring like a bad ground or loose connection somewhere. Or there may be a short somewhere. If the problem persists with the alternator disconnected then look for a short. There may be a short in the horn or somewhere else. Try disconnecting things one at a time to see if you can isolate the cause. __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past.

08-12-2023, 06:35 AM	#4
TraVeler Junior Member Join Date: Jul 2023 Posts: 27	Re: Hello All Been lurkin for a few week ? about ammeter and alternator thanks all Nkaminar I'm in Western nc too down in Polk. Does anyone stock a 6 volt alternator like oreilly advanced autozone napa?

08-12-2023, 10:37 AM	#6
Dick M Senior Member Join Date: May 2010 Location: Ukiah, CA Posts: 477	Re: Hello All Been lurkin for a few week ? about ammeter and alternator Sponsored Links (Register now to hide all advertisements) Jim, that's what the Model A hobby is all about. You are willing to travel two hours to help out a newbie. Congrats to you!!!

08-12-2023, 10:04 PM	#7
TraVeler Junior Member Join Date: Jul 2023 Posts: 27	Re: Hello All Been lurkin for a few week ? about ammeter and alternator I could use the help. Im overwhelmed right now trying to keep them running and i have one more to get out of the weather. I cant get that one(coupe) to start at all. It'll turn over just wont run. Ive got spark at the points. These things sat for 2 or 3 years without moving. I drained the gas out of the tanks but not the carbs. Anyways back to this one that started the thread. The sedan i disconnected the alternator and the ammeter just showed a slight discharge. The number on alternator says 12v negative. Is there a way to test the output voltage of the alternator?

08-11-2023, 08:49 PM	#1
TraVeler Junior Member Join Date: Jul 2023 Posts: 27	Hello All Been lurkin for a few week ? about ammeter and alternator I have 31 sedan that I inherited from my grandfather and the ammeter will go from pegged discharge when it starts to pegged charging then the fuse would blow when I go to rev it up to pull out. So I put a 30 amp breaker on it same scenario pegs it trips the breaker then the car shuts off. I've used the search function but can't find anyone with the same scenario. There is a condenser in the distributor and I've tried to get the timing down with the nurex wrench. Timing Definately not near where the woody idles but it has its own set of problems. I put new plugs in it and it backfires as well. There is a 6 volt alternator as well

08-12-2023, 10:09 PM	#8
TraVeler Junior Member Join Date: Jul 2023 Posts: 27	Re: Hello All Been lurkin for a few week ? about ammeter and alternator Here is part number of alternator. Maybe the problem is this car has been converted to 12v?

08-12-2023, 10:10 PM	#9
TraVeler Junior Member Join Date: Jul 2023 Posts: 27	Re: Hello All Been lurkin for a few week ? about ammeter and alternator 1102394 37a

08-13-2023, 12:46 AM	#11
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,440	Re: Hello All Been lurkin for a few week ? about ammeter and alternator The OP has a major short to ground. That's what burns fuses. The fuse protects the rest of the circuit. The alternator may or may not be involved but something inside would likely be burned melted or damaged enough to create a dead short. Inspect the charging circuit from stem to stern. It could be anywhere in system portions that are not switched. Lights, horn, and electric wiper are isolated if not switched on. Ignition has to be on to run but a short there won't let it run.

08-13-2023, 06:27 AM	#12
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 3,901	Re: Hello All Been lurkin for a few week ? about ammeter and alternator I cannot travel to you to help right now but I posted what I did to get a car running that had sat outside for 5 years. See https://www.fordbarn.com/forum/showthread.php?t=329463 You have a short somewhere. Disconnect all the wiring and use your multi meter to find the short. Google the alternator part number to learn if it is 12 V or 6 V. What voltage battery is installed? The 6 volt battery will have 3 caps on top for filling with distilled water. The 12 volt battery will have 2 caps that fill 3 cells each for a total of 6 cells. __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past.

08-13-2023, 08:09 AM	#13
Rob Doe Senior Member Join Date: Apr 2021 Location: Central Illinois Posts: 495	Re: Hello All Been lurkin for a few week ? about ammeter and alternator Which battery post is grounded to the frame?? __________________ "It ain't what you know for certain that gets ya in trouble. It's what ya know for certain that just ain't so!"

08-13-2023, 08:09 AM	#14
Badpuppy Senior Member Join Date: Dec 2017 Location: Guthrie, OK Posts: 1,145	Re: Hello All Been lurkin for a few week ? about ammeter and alternator All 6V alternators are converted from 12V, and the case stamping isn't changed. The part number is rather meaningless since it is different for the make/model it was originally installed in. You need to identify what type system you have, starting with the battery.

08-13-2023, 08:42 AM	#15
eagle Senior Member Join Date: Aug 2011 Location: Eagle Bend, MN Posts: 2,025	Re: Hello All Been lurkin for a few week ? about ammeter and alternator One thing to remember, the Model A is originally POSITIVE ground. If you dropped a battery in, not knowing that, it would definitely create some havoc. As said above, some alternators have been converted to 6V positive ground so looking at the markings isn't really going to tell you much. Most coils will have a polarity marking on them, usually a + on one side of the primary. If the + is going to the distributor then than is an indicator that it is still positive ground. For sure disconnect the alternator until you figure it out. If you bring the alternator to a competent shop they can tell you if it has been converted. By the way, once you figure this out, DOCUMENT it, put a tag on the alternator and somewhere else on the car. This happens SO often, people make "improvements" to the car and leave no documentation for the next guy. Hydraulic break conversions are the worst for this. Also download a wiring diagram, use the search function here on Fordbarn, they have been posted many times. Good Luck! __________________ "There are some that can destroy an anvil with a teaspoon and shouldn't be allowed to touch anything resembling a tool."

08-13-2023, 09:34 AM	#16
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 3,901	Re: Hello All Been lurkin for a few week ? about ammeter and alternator The stock electrical system is here in detail. https://www.mafca.com/downloads/Semi...ex%20Janke.pdf It is a good resource but your electrical system may have been changed. Common changes are the ignition switch wiring and conversion to an alternator. __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past.

08-13-2023, 01:29 PM	#17
Charlie Stephens Senior Member Join Date: May 2010 Location: Southern California Posts: 7,033	Re: Hello All Been lurkin for a few week ? about ammeter and alternator Be careful you don't burn out the ammeter. Original ones are hard to find. If it goes to 30 amp it is a replacement already. Charie Stephens

08-13-2023, 06:51 PM	#18
TraVeler Junior Member Join Date: Jul 2023 Posts: 27	Re: Hello All Been lurkin for a few week ? about ammeter and alternator The position cable is on the negative battery post the ground cable is on the positive post The ammeter is a 20amp one How many grounds are there?I'll check the schematic I'm pretty sure its still a 6 volt system all the batteries have been 6 volts

08-13-2023, 06:54 PM	#19
TraVeler Junior Member Join Date: Jul 2023 Posts: 27	Re: Hello All Been lurkin for a few week ? about ammeter and alternator Ground cable is attached to trans bolt. I wirewheeled it this am to make sure ground didn't have paint.

08-14-2023, 08:02 AM	#20
Badpuppy Senior Member Join Date: Dec 2017 Location: Guthrie, OK Posts: 1,145	Re: Hello All Been lurkin for a few week ? about ammeter and alternator Check grounding between alternator and battery post. Lack of common reference can lead to high voltage between them. Run AWG #12 between alt. case and battery ground post if necessary. On a similar note, since battery ground has been moved to the bell housing, you also need a connection between ground post and frame (at least #12) for lights and horn.