6V charging issue

SoCalCoupe

SoCalCoupe

Well-known member
When I first got my stock 6V car a few months ago, it wouldn't charge at all. When applying voltage directly to the field with a jumper for a few moments, the charging needle moved well into the charge zone.



I replaced the voltage regulator and it worked fine for a while.



Now, when the car gets fully warmed up and hot, it stops charging as indicted by a 6V reading on the battery at all RPMs and a rock steady neutral ammeter needle.


When the car is started cold, it seems to charge as it should, indicated by a voltage reading at the battery that increases with RPM and the ammeter needle in the charge zone.


I've replaced the generator brushes and brush springs and lightly sanded the commutator to give it a good clean surface.


I've added a second ground wire from the generator case to the voltage regulator with good soldered connectors.


All of the charging/battery wires and connections show 0 ohms with an analog ohmmeter.



I removed, wire-brushed and reconnected all the connections.



When the car is cold or warming up and charging, the ammeter needle vibrates excessively.


MAYBE another new voltage regulator, sort of sounds like the problem, but I don't like "Easter egging," just replacing parts to see what happens without having a really good idea of what's wrong.


What next?
 
Sounds like your battery may finally be fully charged. It takes very little current to run a car once it's warmed up. Try this : turn on he headlights while it's running. It should show a short discharge. When you give your engine some throttle, it will probably go to the charge side. If it does, it looks like everything is OK.
 
I think Tubman has given good advice. From the problem you described, I don’t think you have a problem.
 
SoCal, You are only guessing by replacing parts at random. Need to test with an automotive generator meter test set (analog voltmeter and ammeter) to establish the regulator settings under various load conditions. Until you do that you wont know whats going on. I suspect that the voltage regulator may be set out of specs. With some revs up the charging voltage should be around 7.5 volts. Just because you have a new reproduction regulator made god knows where it may not be working right or adjusted correctly. Regards, Kevin.
 
Use a digital ohmmeter to determine resistance, especially the resistance between the generator case and the regulator frame - resistance between the two will cause ammeter flutter. I had the same problem and resistance of 0.1 determined by a digital ohmmeter. But you must use an analog voltmeter to determine voltage during a running engine - ignition will interfere with a digital voltmeter. I have set my regulator at 7.2 volts - everything OK. My regulator is a Borg Warner.
 
I had a very similar problem less the ammeter. I had ordered a new regulator from Dennis Carpenter to replace the original none functioning one that came in my 50 Custom. I chased my tail trying to maintain a charge voltage.
I bought a replacement from Napa Auto and charge voltage is a little low at 6.8vdc but it maintains that voltage perfectly.
 
The O/P explicitly states that he has an ammeter on his "stock 6 volt car", which will not show an increase in voltage. He should check it with a multi-meter.
 
tubman said:
The O/P explicitly states that he has an ammeter on his "stock 6 volt car", which will not show an increase in voltage. He should check it with a multi-meter.
Click to expand...

Tubman's #2 and #7 posts are spot on!! I had a similar question on my '47 six volt system. There's a great regulator trouble shooting procedure in the 1942 to 1948 Shop Manual, beginning on page R-12.

My regulator did need adjusting per the manual....not that hard with a multi-meter. I cleaned the points and reset the cutout, current control, and voltage adjustment.

My dash amp meter stays in the center zone, except when turning on the headlights, heater, and radio. After a while at rpm's, it settles back in the center.

I had replaced the regulator with a new one from Mac Van Pelt five years ago when I first got the car. It worked perfectly for a long time until wear and tear finally caught up with it. Rather than putting on yet another new one, I thought I'd try to fix this one first. I enjoyed the learning process, and the satisfaction of doing it myself.:)
 
tubman said:
Sounds like your battery may finally be fully charged. It takes very little current to run a car once it's warmed up. Try this : turn on he headlights while it's running. It should show a short discharge. When you give your engine some throttle, it will probably go to the charge side. If it does, it looks like everything is OK.
Click to expand...


Great idea; tried it out today. Started up cold and got indications from the ammeter the car was a little into the charge zone. Got it all warmed up; then the ammeter indicated the car had stopped charging. Turned on the headlights and ran a few minutes; the needle was well into the discharge zone the whole time. Engine speed and revving wouldn't move the needle at all.



Didn't run the battery down as much as I thought. After getting home, it was only on the charger a couple of hours before it turned green. I had visions of sitting by the side of the road with a dead battery waiting a couple of hours for a flatbed to take me home so didn't run the headlight experiment for too long.



After four outings starting cold then getting fully warmed up, I'm convinced the car charges fine when cold and then stops charging when it's hot under the hood.


Kevin is right,
koates said:
SoCal, You are only guessing by replacing parts at random. Need to test with an automotive generator meter test set (analog voltmeter and ammeter) to establish the regulator settings under various load conditions. Until you do that you wont know whats going on. I suspect that the voltage regulator may be set out of specs. With some revs up the charging voltage should be around 7.5 volts. Just because you have a new reproduction regulator made god knows where it may not be working right or adjusted correctly. Regards, Kevin.
Click to expand...


Nevertheless, I'm going to shop around and find another solid state or made in USA voltage regulator to throw at it. This is a tough one. Not real easy figure out which of the dozens of choices on eBay are compatible. Don't know that any of catalog guys sell anything but Chxxxse stuff.

I'm also going to see my new San Diego Early Ford V8 buddies this Wednesday and ask about shop that does 6V electrical work for testing.


I like RKS.PA idea too. It would be really satisfying to troubleshoot and fix it. Where do I find a copy of this shop manual? I'll look around. Was this an adjustable regulator or did you get into the whole bending tabs thing?

RKS.PA said:
Tubman's #2 and #7 posts are spot on!! I had a similar question on my '47 six volt system. There's a great regulator trouble shooting procedure in the 1942 to 1948 Shop Manual, beginning on page R-12.

My regulator did need adjusting per the manual....not that hard with a multi-meter. I cleaned the points and reset the cutout, current control, and voltage adjustment.

My dash amp meter stays in the center zone, except when turning on the headlights, heater, and radio. After a while at rpm's, it settles back in the center.

I had replaced the regulator with a new one from Mac Van Pelt five years ago when I first got the car. It worked perfectly for a long time until wear and tear finally caught up with it. Rather than putting on yet another new one, I thought I'd try to fix this one first. I enjoyed the learning process, and the satisfaction of doing it myself.:)
Click to expand...
 
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SoCal, I did the tab bending adjustment per the shop manual which changes the spring
tension...it's easy...and then you test the result with your multi meter.

I think those shop manuals are readily available, but I've had mine a while. If you can't find one and want to try to adjust your current regulator, I'll scan my pages that apply and send it to you as an attachment to a PM to you.
 
Socalcoupe, I have a new regulator on the shelf (made in USA, no brand name, I believe D.C. was the source) which works PERFECTLEY when cold, 3 miles on a summer day and that ends, zero charge. I installed another one,( sourced at a jobber, trade name, made in USA, blue with a metallic sticker on it which described the procedure to polarize). It sorta worked but only charged at about 6 volts on a battery with a real low charge. I adjusted the regulator so it charges in the mid 7 range on a low battery and maintains a resting 6.4 volts. I have 2 more on the shelf which are new but may or may not be good, maybe they will adjust to work properly? The point is I believe you have to learn to adjust these regulators; not difficult but do not get in a rush; or take the VEHICLE to a auto electric shop that has OLD GUYS working there.
 
on your explanation of the no charge problem you state that you applied voltage to the field wire all the years i’ve ben doing this is you always ground the field wire and check it out with a volt meter on the battery at different RPM at 12 - 15 hundred rpm it should be @ 7.5 volts good luck
 
joe 1950 said:
on your explanation of the no charge problem you state that you applied voltage to the field wire all the years i’ve ben doing this is you always ground the field wire and check it out with a volt meter on the battery at different RPM at 12 - 15 hundred rpm it should be @ 7.5 volts good luck
Click to expand...

Grounding the field wire is only for generators (Delco) on GM cars and some others. On old Ford (Autolite) generators the field terminal connects to the armature terminal to test the generator output. This is because there are two different ways that the field coils are connected inside generators. You need to know what generator you have. Regards, Kevin.
 
Don T said:
Socalcoupe, I have a new regulator on the shelf (made in USA, no brand name, I believe D.C. was the source) which works PERFECTLEY when cold, 3 miles on a summer day and that ends, zero charge. I installed another one,( sourced at a jobber, trade name, made in USA, blue with a metallic sticker on it which described the procedure to polarize). It sorta worked but only charged at about 6 volts on a battery with a real low charge. I adjusted the regulator so it charges in the mid 7 range on a low battery and maintains a resting 6.4 volts. I have 2 more on the shelf which are new but may or may not be good, maybe they will adjust to work properly? The point is I believe you have to learn to adjust these regulators; not difficult but do not get in a rush; or take the VEHICLE to a auto electric shop that has OLD GUYS working there.
Click to expand...
Thanks Don. Identical symptoms, very helpful. Opinion is split roughly 2/2 on adjust it/don't adjust it. I do have a good procedure; think I'm going to go ahead and attempt it.
 
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Trying to wrap my head around how a voltage regulator works. Got the 42-48 shop manual with adjustment procedure as RKS.PA recommended. Followed the procedure below and got significantly different readings.


"Check Cut-in Voltage" I went through that part with the (-) lead connected to the generator armature and the (+) to ground. At idle I got zero volts and as I slowly revved the engine it climbed to 6.5 and then cut-in quickly, went to 7.0 and all the way to 7.5 at high RPM. What was confusing was words in step 2 saying "The reading just before the needle drops will be the closing voltage. This should be between 6.4 and 7.0 volts with regulator cover in place." As I revved up the engine, my needle didn't drop down from a higher voltage to a reading between "6.4 and 7.0 volts," it jumped up from about 6.0 volts. As I "Decrease engine speed slowly; meter needle will dip quickly when points open. Points should open at 4.2 to 4.8 volts." Didn't see that, I did see needle dip quickly at about 6 volts.



Sounds like the cutout is closed between 4.5 and 6.7 volts and otherwise open? Why would the cutout be closed on the way down all the way to 4.5 volts? Wouldn't the battery be seriously "motoring" the generator at that point?


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Never could get the voltage regulator to respond as described in the the '42-'48 manual. I recall from an electronics class 40 years ago that the function of the cutout as described in the manual is a 'bi-stable'. It's supposed to close going up at a higher voltage than when it opens going down "6.4 and 7.0 volts" and open going down at "4.2 to 4.8 volts."


With the third regulator in 6 months it seems to keep the battery charged as indicated by a 6.4-6.5 volt reading immediately after shutting down. I'm going to call it a day and move on to something else.
 
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SoCalCoupe said:
Never could get the voltage regulator to respond as described in the the '42-'48 manual. I recall from an electronics class 40 years ago that the function of the cutout as described in the manual is a 'bi-stable'. It's supposed to close going up at a higher voltage than when it opens going down "6.4 and 7.0 volts" and supposed to open going down at a lower voltage than when it closes going up "4.2 to 4.8 volts."


With the third regulator in 6 months it seems to keep the battery charged as indicated by a 6.4-6.5 volt reading immediately after shutting down. I'm going to call it a day and move on to something else.
Click to expand...


Welcome to the dead regulator club. Pretty much exactly what happened to me. Rebuilt genny, new main wire harness, all new grounds, new battery....

Bad regulator out of the box. It has been several months and about 2500 miles and still going strong and I am seeing your same results. Hopefully we will be good to go.
 
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