not charging- how to diagnose

Battery not charging. I have flashed the generator, checked battery terminals, Gen connections. Generator is Auto lite gdz 481? 7 I think. How do I connect.my tester to generator?

Right connector is marked "F". Middle appears to be ground, and.left.should be armature. Voltage regulator appears to be connected correctly.
Thanks for the help.

Rick Estes

Great! That's exactly the kind of thing I want to know. I'll try that tomorrow.
Thank you.

Rick Estes

Ok. Well my 48 is 12 volt and so far the lights work. The ammeter shows discharge when I turn them on, but it never shows charge with lights off and engine running. Meter shows 11+ volts at battery with engine running.
Thanks again.

Rick Estes

WeeWilly, you really seem to know your stuff about electrical. Thanks for the info on how to test a condenser (on another thread). What about hooking a lead from the positive side of the bat to the armature grounding side to see if it turns like a motor. I always heard every generator is a motor and vice versa. thanks Joe Wadoyado

I don't know yet, but I assume Wee Willy's test will tell me that. Also I have been driving the Jeep sporadically for years.
Thanks for asking. I'm almost ready to test it now.

Rick Estes

I would probably check to make sure the regulator is grounded...and the points are not seized.

1- 1946 CJ2A
2- 1949 CJ3A

Ok. I took the cover off the VR, cleaned the points as well as I could with a strip of sandpaper, they are free, checked the ground to the fender, but still not charging. I am looking for a new VR but no luck so far.
Any other ideas?
Thank you.

Rick Estes

We still do not know if the generator & regulator are 12 Volts. Any 6 volt generator will read above 14 volts tested that way, at least all of mine have. What indications do you have that your units are 12 volt?

Note: A 6 volt generator will charge at 12 volts for a short time. It will get hot fairly fast though. The heat will probably de-solder the commutator. AMHIK! It only took about 15 minutes for that to happen.

My guess as to your charging problem is that the system is still 6 Volt. The regulator thinks that the battery is fully charged, since it is over 9 Volts, & thus is not trying to charge it. Also the current limiting part of the regulator may be shutting the charging system off due to excessive current back feeding through the regulator. I may be wrong about that though.

Do you have any numbers from any data plate on either the generator or the regulator? From those numbers, we can find out what voltage your system originally was.

It is not common for folks to rewind a generator to 12 volts. It is almost always cheaper to buy a 12 Volt generator.

IHTH, Cpt Logger.

Edited by cpt logger - 21 Jan. 2017 at 11:05am

Are you sure that the resister is between the battery & the ammeter, not between the ammeter & the ignition switch, or some other load? There is no need for a resister between the ammeter & the battery. The ammeter does not care what the voltage is, it only cares about the amperage.

According to my information, an Auto lite GDZ-4817 is a 6 Volt generator. It was used on the CJs until about 1950.

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
eestes1 Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 12 Feb. 2011 Location: Mineral, VA Status: Offline Points: 1158	Post Options Post Reply Quote eestes1 Report Post Thanks(0) Quote Reply Topic: not charging- how to diagnose Posted: 18 Jan. 2017 at 8:19pm
	Battery not charging. I have flashed the generator, checked battery terminals, Gen connections. Generator is Auto lite gdz 481? 7 I think. How do I connect.my tester to generator? Right connector is marked "F". Middle appears to be ground, and.left.should be armature. Voltage regulator appears to be connected correctly. Thanks for the help.
	Rick Estes

WeeWilly Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 07 May 2009 Location: Clayton IN Status: Offline Points: 3423	Post Options Post Reply Quote WeeWilly Report Post Thanks(0) Quote Reply Posted: 18 Jan. 2017 at 9:57pm
	One way to test generator is take the field and armature wire off at the generator. Then start the motor and using a volt meter connected to the armature post and ground and using a jumper wire from the field post to ground you should get around 7 volts at idle speed for a 6 volt generator. If you get that reading then the problem is in the wiring or regulator. Jim
	47 CJ2A (Ranch Hand) 48 CJ2A, 48 Willys truck, T3C 3782, M274 (Military Mule)

eestes1 Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 12 Feb. 2011 Location: Mineral, VA Status: Offline Points: 1158	Post Options Post Reply Quote eestes1 Report Post Thanks(0) Quote Reply Posted: 18 Jan. 2017 at 10:44pm
	Great! That's exactly the kind of thing I want to know. I'll try that tomorrow. Thank you.
	Rick Estes

WeeWilly Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 07 May 2009 Location: Clayton IN Status: Offline Points: 3423	Post Options Post Reply Quote WeeWilly Report Post Thanks(0) Quote Reply Posted: 18 Jan. 2017 at 11:16pm
	Glad to be of a little help. When I restored my 47 I tested the generator on the bench using a cordless drill to rotate it for the same test. The reason for taking the wires off is when the field is grounded the generator will put out its max voltage according to the RPM and could burn out 6 volt light bulbs and etc.. Jim
	47 CJ2A (Ranch Hand) 48 CJ2A, 48 Willys truck, T3C 3782, M274 (Military Mule)

eestes1 Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 12 Feb. 2011 Location: Mineral, VA Status: Offline Points: 1158	Post Options Post Reply Quote eestes1 Report Post Thanks(0) Quote Reply Posted: 18 Jan. 2017 at 11:34pm
	Ok. Well my 48 is 12 volt and so far the lights work. The ammeter shows discharge when I turn them on, but it never shows charge with lights off and engine running. Meter shows 11+ volts at battery with engine running. Thanks again.
	Rick Estes

WeeWilly Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 07 May 2009 Location: Clayton IN Status: Offline Points: 3423	Post Options Post Reply Quote WeeWilly Report Post Thanks(0) Quote Reply Posted: 19 Jan. 2017 at 12:37am
	With the test I mentioned with a 12 volt generator you would get around 13 volts. Jim
	47 CJ2A (Ranch Hand) 48 CJ2A, 48 Willys truck, T3C 3782, M274 (Military Mule)

wadoyado Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member Joined: 29 Sep. 2016 Location: Mi. Status: Offline Points: 728	Post Options Post Reply Quote wadoyado Report Post Thanks(0) Quote Reply Posted: 19 Jan. 2017 at 4:23am
	WeeWilly, you really seem to know your stuff about electrical. Thanks for the info on how to test a condenser (on another thread). What about hooking a lead from the positive side of the bat to the armature grounding side to see if it turns like a motor. I always heard every generator is a motor and vice versa. thanks Joe Wadoyado

TERRY Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member Joined: 22 May 2007 Location: BOULDER COLORADO Status: Offline Points: 3400	Post Options Post Reply Quote TERRY Report Post Thanks(0) Quote Reply Posted: 19 Jan. 2017 at 3:07pm
	Has the generator been converted to 12V ?
	BOULDER 48 2A

eestes1 Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 12 Feb. 2011 Location: Mineral, VA Status: Offline Points: 1158	Post Options Post Reply Quote eestes1 Report Post Thanks(0) Quote Reply Posted: 19 Jan. 2017 at 3:22pm
	I don't know yet, but I assume Wee Willy's test will tell me that. Also I have been driving the Jeep sporadically for years. Thanks for asking. I'm almost ready to test it now.
	Rick Estes

eestes1 Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 12 Feb. 2011 Location: Mineral, VA Status: Offline Points: 1158	Post Options Post Reply Quote eestes1 Report Post Thanks(0) Quote Reply Posted: 19 Jan. 2017 at 3:53pm
	The above test shows 15+ volts. Where to now? Thanks!
	Rick Estes

athawk11 Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 18 Jan. 2012 Location: Arvada,Colorado Status: Offline Points: 4151	Post Options Post Reply Quote athawk11 Report Post Thanks(0) Quote Reply Posted: 19 Jan. 2017 at 4:35pm
	I would probably check to make sure the regulator is grounded...and the points are not seized.
	1- 1946 CJ2A 2- 1949 CJ3A

eestes1 Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 12 Feb. 2011 Location: Mineral, VA Status: Offline Points: 1158	Post Options Post Reply Quote eestes1 Report Post Thanks(0) Quote Reply Posted: 19 Jan. 2017 at 5:18pm
	The points in the regulator? How do I check that? Thanks.
	Rick Estes

eestes1 Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 12 Feb. 2011 Location: Mineral, VA Status: Offline Points: 1158	Post Options Post Reply Quote eestes1 Report Post Thanks(0) Quote Reply Posted: 20 Jan. 2017 at 11:51pm
	Ok. I took the cover off the VR, cleaned the points as well as I could with a strip of sandpaper, they are free, checked the ground to the fender, but still not charging. I am looking for a new VR but no luck so far. Any other ideas? Thank you.
	Rick Estes

WeeWilly Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 07 May 2009 Location: Clayton IN Status: Offline Points: 3423	Post Options Post Reply Quote WeeWilly Report Post Thanks(0) Quote Reply Posted: 21 Jan. 2017 at 12:34am
	Glad to hear that the gen. is OK. Check the wiring and make sure it is OK also and if it is the only thing left is a bad reg. I see them on ebay for sale and most venders have them also. Jim
	47 CJ2A (Ranch Hand) 48 CJ2A, 48 Willys truck, T3C 3782, M274 (Military Mule)

cpt logger Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 23 Sep. 2012 Location: Western Colorad Status: Offline Points: 3043	Post Options Post Reply Quote cpt logger Report Post Thanks(0) Quote Reply Posted: 21 Jan. 2017 at 10:55am
	We still do not know if the generator & regulator are 12 Volts. Any 6 volt generator will read above 14 volts tested that way, at least all of mine have. What indications do you have that your units are 12 volt? Note: A 6 volt generator will charge at 12 volts for a short time. It will get hot fairly fast though. The heat will probably de-solder the commutator. AMHIK! It only took about 15 minutes for that to happen. My guess as to your charging problem is that the system is still 6 Volt. The regulator thinks that the battery is fully charged, since it is over 9 Volts, & thus is not trying to charge it. Also the current limiting part of the regulator may be shutting the charging system off due to excessive current back feeding through the regulator. I may be wrong about that though. Do you have any numbers from any data plate on either the generator or the regulator? From those numbers, we can find out what voltage your system originally was. It is not common for folks to rewind a generator to 12 volts. It is almost always cheaper to buy a 12 Volt generator. IHTH, Cpt Logger. Edited by cpt logger - 21 Jan. 2017 at 11:05am

eestes1 Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 12 Feb. 2011 Location: Mineral, VA Status: Offline Points: 1158	Post Options Post Reply Quote eestes1 Report Post Thanks(0) Quote Reply Posted: 21 Jan. 2017 at 11:12am
	Thanks to you both! The generator is an Auto lite GDZ 481_(7?). I'll see if I can read the other numbers on the metal tag. The regulator was replaced several years ago and I'll look for numbers on it also. I'm pretty sure I got a 12 volt regulator at that time because the Jeep had been "converted" to 12 volts when I got it, at least it had a 12 volt battery and a resistor between the battery and ammeter. And I've driven it sporadically for years with no problem. Well, not this problem!😉
	Rick Estes

cpt logger Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 23 Sep. 2012 Location: Western Colorad Status: Offline Points: 3043	Post Options Post Reply Quote cpt logger Report Post Thanks(0) Quote Reply Posted: 21 Jan. 2017 at 12:10pm
	Are you sure that the resister is between the battery & the ammeter, not between the ammeter & the ignition switch, or some other load? There is no need for a resister between the ammeter & the battery. The ammeter does not care what the voltage is, it only cares about the amperage. According to my information, an Auto lite GDZ-4817 is a 6 Volt generator. It was used on the CJs until about 1950.

eestes1 Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 12 Feb. 2011 Location: Mineral, VA Status: Offline Points: 1158	Post Options Post Reply Quote eestes1 Report Post Thanks(0) Quote Reply Posted: 21 Jan. 2017 at 1:31pm
	OK, with red face, here's what I found: the resistor is connected to the coil and either the ignition switch or the ammeter I think ( can't get under the dash to trace that wire right now). The coil is 6 volt. The regulator is 12 volt- "2192 12 volt neg/POS". The battery is 12 volt. Apparently the generator and starter are 6 volt. How did this Jeep run? When I got it I just tried to keep it going and out of the junk yard and didn't really need to dig into it. Obviously I should have! So if you guys haven't given up on Scabby and me, I would like to hear your thoughts. Can I replace the battery and regulator with 6 volt ones and trash the resistor? I would go back to 6 volt headlights. Thanks.
	Rick Estes