The Ford Barn

Woodie1 · 10-15-2022, 05:09 PM

The other day we went to drive our 39 & the battery was dead. I put the charger on it on a quick charge & it started up after a minute or so. I drove 20 miles & didn't think any thing of it. Tried to start it & it was dead again. I did a slow charge of the battery & it has started up fine several times. According to my battery tester & a hydrometer the battery was charged fully. I also had the battery checked at an auto parts store & they said it was good. I had it charged to 6.25 volts & the next day it was down to 6.17 volts. I've tried the parasitic draw test & the meter shows .025 amp. I've done other tests found on Ford Barn & in books I have but nothing gives me a good clue as to the source of the problem. The battery gauge on the dash never gets into the normal range. It's always a little low. The system is a 6 volt & the generator is a single post 2 brush. Any hints would be appreciated.

TJ · 10-15-2022, 05:26 PM

First question is how old is the battery? Did the auto parts store do a load test on it?

Woodie1 · 10-15-2022, 06:19 PM

The battery is a little over a year old. The test they did & I did was with a hand held harbor freight unit with a toggle on it for doing a load test. They tried another hand held unit which appeared more detailed but he wasn't sure it was working on the 6 volt battery.

paul2748 · 10-15-2022, 06:26 PM

Did you check the output of the generator? What kind of volts are you getting at the battery with the engine running (at around 1000 rpm's) ?

oldbugger · 10-15-2022, 06:32 PM

been there dun this, remove fuses one by one while checking the .025 draw, when you get no draw you found your problem circuit.

Woodie1 · 10-15-2022, 07:00 PM

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I don't see anymore than 6.25 at the battery with it at faster than idle speed. There are no fuses in the system.

drolston · 10-15-2022, 07:18 PM

Sounds like the generator is not generating. Should get over 7 volts at the battery with the engine at 1000 rpm or more.

If 39 Standard, maybe the cutout on the generator has failed open. If Deluxe, maybe it is a regulator malfunction or bad connection. Check the connections and be sure the generator is well grounded.

Woodie1 · 10-15-2022, 08:10 PM

I figured I should have over 7 volts also. I cleaned the front mounting bracket of the generator so it had a clean surface to the aluminum intake. I have tried tests of the regulator but did not see the voltage that is supposed to be there.

Anteek29 · 10-15-2022, 09:32 PM

Definitely a problem with cutout or regulator...which one do you have? I'd get the charging voltage where it should be 7.2 - 7.5 volts and then trace where that 0.25 amp is going.

corvette8n · 10-16-2022, 07:01 AM

I wouldn’t think in a ‘39 there shouldn’t be any current draw with the key switch off. Don’t forget to check all of your grounds they need to be clean, tight and bright.

Woodie1 · 10-16-2022, 07:56 AM

The car has a regulator. I'm going to check things over again tomorrow. I hope I can understand it better then.

Bill OH · 10-16-2022, 08:44 AM

Are your gauges connected to the battery side of the ignition switch?. The gauges are voltmeters and the amount of current that you mention suggests that your gauges are connected to the battery side of the ignition switch. I have seen this on two occasions. A real sleeper!!!

Clean the contacts in the regulator with very fine sand paper doubled over and pulled thru the contacts while holding the contacts closed. You may need to connect a analog voltmeter to the BAT terminal on the regulator and ground and adjust the field voltage control to 7.2 - 7.4 volts by bending the spring anchor to increase spring tension and while the engine is turning say 1500 rpm.

Anteek29 · 10-16-2022, 10:22 AM

Clean the contacts in the regulator with very fine sand paper doubled over and pulled thru the contacts while holding the contacts closed. You may need to connect a analog voltmeter to the BAT terminal on the regulator and ground and adjust the field voltage control to 7.2 - 7.4 volts by bending the spring anchor to increase spring tension and while the engine is turning say 1500 rpm.[/QUOTE]

Great suggestion to start with cleaning the contacts! I'd advise you to have a pertinent shop manual to guide you through regulator adjustment procedures...it can be a mysterious labyrinth under the cover.

Woodie1 · 10-16-2022, 06:26 PM

I've cleaned the contacts in the past but it won't hurt to try again. The adjusting does sound technical. I'm sure I would have to be very careful doing these adjustments while it is running.

Bill OH · 10-16-2022, 09:31 PM

You might also try polarizing the generator by removing the field wire from the regulator and momentarily touching it to the battery post on the regulator. Then connect your analog voltmeter to the BAT post and the other to ground and see what the voltage is with the engine at about 1500 rpm - looking for 7.2 - 7.4 volts. If not, either adjust the field control in the regulator or purchase a new regulator. If you replace the regulator, then again polarize the generator just to be on the safe side. You should test the output of the generator by connecting the analog voltmeter to the BAT terminal on the regulator, the other lead to ground, touching the field wire to the ARM terminal on the regulator and at the same time run the engine to 1500 rpm or more - voltmeter should show more than 7 volts - if 7 or more generator is good and the regulator needs adjusting or replaced. If less than 7 volts, then take generator to a repair shop. Good experience!!!

Woodie1 · 10-17-2022, 09:30 AM

I'm not doing well with the circuit testing. The book calls for a 3/4 ohm resistor which I don't have & I sorta guess on the 1500 rpm it call for. Things do look better this morning. I ran some doubled up paper across the regulator contacts & then I used 220 sand paper on the screw terminals & the wire terminals. I started the car & ran it at a fast idle for about 1 minute & now my battery gauge shows high normal range. It never even got into the normal range before. Just a touch below it. The battery has been installed wrong ever since we got the car last year. I figured if it ran, leave it alone.

19Fordy · 10-17-2022, 09:45 AM

Woodie1: Perhaps I missed something but, please let us know what you mean when you say the battery was installed wrong.

Glad you solved the problem.

Woodie1 · 10-17-2022, 09:54 AM

It is installed modern way, negative ground.

Bill OH · 10-17-2022, 10:11 AM

Battery should be installed positive ground. Polarize the generator by touching the field wire from the regulator to the BAT terminal on the regulator.. And run the generator output test that I outlined above.

The ignition coil is designed to run with positive ground!!!! Switch battery to positive ground.!!

Woodie1 · 10-17-2022, 11:36 AM

I tested voltage at the regulator battery terminal to a ground & I now see 8.3 volts. I have not change the battery polarity yet. Now I'm confused by the book at this point. One parts says to adjust the regulator armature on the left to change voltage & another picture says to adjust the cutout armature on the right to raise or lower voltage. Which one is right? The left coil or the right coil?

10-15-2022, 05:09 PM	#1
Woodie1 Senior Member Join Date: Mar 2011 Location: W. Mich. Posts: 532	dead battery The other day we went to drive our 39 & the battery was dead. I put the charger on it on a quick charge & it started up after a minute or so. I drove 20 miles & didn't think any thing of it. Tried to start it & it was dead again. I did a slow charge of the battery & it has started up fine several times. According to my battery tester & a hydrometer the battery was charged fully. I also had the battery checked at an auto parts store & they said it was good. I had it charged to 6.25 volts & the next day it was down to 6.17 volts. I've tried the parasitic draw test & the meter shows .025 amp. I've done other tests found on Ford Barn & in books I have but nothing gives me a good clue as to the source of the problem. The battery gauge on the dash never gets into the normal range. It's always a little low. The system is a 6 volt & the generator is a single post 2 brush. Any hints would be appreciated.

10-15-2022, 05:26 PM	#2
TJ Senior Member Join Date: May 2010 Location: Napa,California Posts: 6,566	Re: dead battery First question is how old is the battery? Did the auto parts store do a load test on it?

10-15-2022, 06:19 PM	#3
Woodie1 Senior Member Join Date: Mar 2011 Location: W. Mich. Posts: 532	Re: dead battery The battery is a little over a year old. The test they did & I did was with a hand held harbor freight unit with a toggle on it for doing a load test. They tried another hand held unit which appeared more detailed but he wasn't sure it was working on the 6 volt battery.

10-15-2022, 06:26 PM	#4
paul2748 Senior Member Join Date: May 2010 Location: Midland Park, NJ Posts: 4,290	Re: dead battery Did you check the output of the generator? What kind of volts are you getting at the battery with the engine running (at around 1000 rpm's) ? __________________ 48 Ford Conv 56 Tbird 54 Ford Victoria

10-15-2022, 06:32 PM	#5
oldbugger Senior Member Join Date: May 2010 Location: Holland Mi Posts: 705	Re: dead battery been there dun this, remove fuses one by one while checking the .025 draw, when you get no draw you found your problem circuit.

10-15-2022, 07:00 PM	#6
Woodie1 Senior Member Join Date: Mar 2011 Location: W. Mich. Posts: 532	Re: dead battery Sponsored Links (Register now to hide all advertisements) I don't see anymore than 6.25 at the battery with it at faster than idle speed. There are no fuses in the system.

10-15-2022, 07:18 PM	#7
drolston Senior Member Join Date: Jun 2014 Location: Williamsburg, VA Posts: 1,811	Re: dead battery Sounds like the generator is not generating. Should get over 7 volts at the battery with the engine at 1000 rpm or more. If 39 Standard, maybe the cutout on the generator has failed open. If Deluxe, maybe it is a regulator malfunction or bad connection. Check the connections and be sure the generator is well grounded.

10-15-2022, 08:10 PM	#8
Woodie1 Senior Member Join Date: Mar 2011 Location: W. Mich. Posts: 532	Re: dead battery I figured I should have over 7 volts also. I cleaned the front mounting bracket of the generator so it had a clean surface to the aluminum intake. I have tried tests of the regulator but did not see the voltage that is supposed to be there.

10-15-2022, 09:32 PM	#9
Anteek29 Senior Member Join Date: Dec 2014 Location: Santa Maria, CA Posts: 1,008	Re: dead battery Definitely a problem with cutout or regulator...which one do you have? I'd get the charging voltage where it should be 7.2 - 7.5 volts and then trace where that 0.25 amp is going. __________________ Alan 1929 Special Coupe 1941 Pick-Up 1955 Victoria

10-16-2022, 07:01 AM	#10
corvette8n Senior Member Join Date: Jul 2010 Location: 36 miles north of Albany NY Posts: 3,198	Re: dead battery I wouldn’t think in a ‘39 there shouldn’t be any current draw with the key switch off. Don’t forget to check all of your grounds they need to be clean, tight and bright.

10-16-2022, 07:56 AM	#11
Woodie1 Senior Member Join Date: Mar 2011 Location: W. Mich. Posts: 532	Re: dead battery The car has a regulator. I'm going to check things over again tomorrow. I hope I can understand it better then.

10-16-2022, 08:44 AM	#12
Bill OH Senior Member Join Date: May 2010 Posts: 453	Re: dead battery Are your gauges connected to the battery side of the ignition switch?. The gauges are voltmeters and the amount of current that you mention suggests that your gauges are connected to the battery side of the ignition switch. I have seen this on two occasions. A real sleeper!!! Clean the contacts in the regulator with very fine sand paper doubled over and pulled thru the contacts while holding the contacts closed. You may need to connect a analog voltmeter to the BAT terminal on the regulator and ground and adjust the field voltage control to 7.2 - 7.4 volts by bending the spring anchor to increase spring tension and while the engine is turning say 1500 rpm.

10-16-2022, 10:22 AM	#13
Anteek29 Senior Member Join Date: Dec 2014 Location: Santa Maria, CA Posts: 1,008	Re: dead battery Clean the contacts in the regulator with very fine sand paper doubled over and pulled thru the contacts while holding the contacts closed. You may need to connect a analog voltmeter to the BAT terminal on the regulator and ground and adjust the field voltage control to 7.2 - 7.4 volts by bending the spring anchor to increase spring tension and while the engine is turning say 1500 rpm.[/QUOTE] Great suggestion to start with cleaning the contacts! I'd advise you to have a pertinent shop manual to guide you through regulator adjustment procedures...it can be a mysterious labyrinth under the cover. __________________ Alan 1929 Special Coupe 1941 Pick-Up 1955 Victoria

10-16-2022, 06:26 PM	#14
Woodie1 Senior Member Join Date: Mar 2011 Location: W. Mich. Posts: 532	Re: dead battery I've cleaned the contacts in the past but it won't hurt to try again. The adjusting does sound technical. I'm sure I would have to be very careful doing these adjustments while it is running.

10-16-2022, 09:31 PM	#15
Bill OH Senior Member Join Date: May 2010 Posts: 453	Re: dead battery You might also try polarizing the generator by removing the field wire from the regulator and momentarily touching it to the battery post on the regulator. Then connect your analog voltmeter to the BAT post and the other to ground and see what the voltage is with the engine at about 1500 rpm - looking for 7.2 - 7.4 volts. If not, either adjust the field control in the regulator or purchase a new regulator. If you replace the regulator, then again polarize the generator just to be on the safe side. You should test the output of the generator by connecting the analog voltmeter to the BAT terminal on the regulator, the other lead to ground, touching the field wire to the ARM terminal on the regulator and at the same time run the engine to 1500 rpm or more - voltmeter should show more than 7 volts - if 7 or more generator is good and the regulator needs adjusting or replaced. If less than 7 volts, then take generator to a repair shop. Good experience!!! Last edited by Bill OH; 10-16-2022 at 09:47 PM.

10-17-2022, 09:30 AM	#16
Woodie1 Senior Member Join Date: Mar 2011 Location: W. Mich. Posts: 532	Re: dead battery I'm not doing well with the circuit testing. The book calls for a 3/4 ohm resistor which I don't have & I sorta guess on the 1500 rpm it call for. Things do look better this morning. I ran some doubled up paper across the regulator contacts & then I used 220 sand paper on the screw terminals & the wire terminals. I started the car & ran it at a fast idle for about 1 minute & now my battery gauge shows high normal range. It never even got into the normal range before. Just a touch below it. The battery has been installed wrong ever since we got the car last year. I figured if it ran, leave it alone. Last edited by Woodie1; 10-17-2022 at 09:44 AM.

10-17-2022, 09:45 AM	#17
19Fordy Senior Member Join Date: May 2010 Location: Coral Springs FL Posts: 11,605	Re: dead battery Woodie1: Perhaps I missed something but, please let us know what you mean when you say the battery was installed wrong. Glad you solved the problem.

10-17-2022, 09:54 AM	#18
Woodie1 Senior Member Join Date: Mar 2011 Location: W. Mich. Posts: 532	Re: dead battery It is installed modern way, negative ground.

10-17-2022, 10:11 AM	#19
Bill OH Senior Member Join Date: May 2010 Posts: 453	Re: dead battery Battery should be installed positive ground. Polarize the generator by touching the field wire from the regulator to the BAT terminal on the regulator.. And run the generator output test that I outlined above. The ignition coil is designed to run with positive ground!!!! Switch battery to positive ground.!! Last edited by Bill OH; 10-17-2022 at 10:16 AM.

10-17-2022, 11:36 AM	#20
Woodie1 Senior Member Join Date: Mar 2011 Location: W. Mich. Posts: 532	Re: dead battery I tested voltage at the regulator battery terminal to a ground & I now see 8.3 volts. I have not change the battery polarity yet. Now I'm confused by the book at this point. One parts says to adjust the regulator armature on the left to change voltage & another picture says to adjust the cutout armature on the right to raise or lower voltage. Which one is right? The left coil or the right coil?