Ford NAA charging issue

TXFordNAA

Member
I recently got my spark and fuel issues resolved thanks to those on this forum. I am starting a new thread as the topic I am dealing with now is so different and will hopefully help others find this topic. I want to say i have reviewed older post on this topic, but many deal with altered equipment.

Tractor: Ford 1953 NAA with original 6v Pos Ground system.
Issue: There is no charge registering on amp meter on the dash - shows straight up 0 running or not

In order to solve spark issue, i recently replaced the B Type voltage regulator as the old one was fried (guts melted). The part # for the new VR is FAG10505A, which is listed for the NAA and is type B from my understanding. I also put a new 6V battery, new points and condenser and have good continuity on all wiring from the BAT terminal of the VR thru the ignition switch and on to the coil.

I also polarized the VR by removing the FIELD wire from VR and touching to the BAT terminal with the battery hooked up (pos ground). This was the polarizing instructions that came with the VR. I had rewired the tractor a few years ago and at that time ripped all the old out as it was installed wrong according to the wiring diagrams and it did start showing a charge at that time, but that was short lived. When I start the tractor the Amp Meter on the dash stays at zero now. In the past it would sometimes move to the minus range and sometimes it would show a very strong (almost too much) charge reading.

I will be checking for good contacts on all wiring up to the VR this evening by checking continuity and connections...I do have some preliminary questions for the checks to do this evening.

1. I read on a prior post to check the Generator to see if it motors by connecting the battery "hot" (meaning negative post of battery since it's POS ground) to the Field and Armature post of the generator. I am a little unclear on this procedure...I can run a wire from the Neg post of battery to the Generator, but do i split the wire and hook to both the ARM and FLD post on generator at same time???

2. I know the rear most post on the GEN is the ARM, but have no clue with of the remaining 2 post on the barrel of the GEN are Field and Ground. I don't want to assume by the wiring as there is a chance they are not connected to the correct places as I am the one who hooked them up. I will try and clean the GEN surface and look for a stamp unless there is an easy way to tell.

3. I also read on here that there is a difference between a FULL POLARIZATION and doing it at the VR as i have already done. Do I need to POLARIZE at the GEN also by using jump wire from the ARM to the FLD on the generator or is this pointless after having done the polarization at the VR?

I will post what I find this evening or tomorrow morning...if anyone has time to offer guidance on the above or any other procedures I should do, please let me know. I don't want to fry my new shiny VR, Battery or Points though.

Thanks.....Brad
a262268.jpg
 
Sorry for crooked pics...not sure why it does this

I am now attaching the wiring diagram i will be using to verify my connections
 
Before getting too deep into this, have you actually tested for charge?

Possibly the amp meter is bad, especially if it doesn't show discharge when the ign or lights are on, engine off.

You need a volt meter to test the output. Put it across the battery, crank the engine, bring the RPM up. If the reading stays low, 6 v or under, it is not charging. A good reading would be around 7-7 1/2 volts.

1. If you want to motor the gen, yes, connect 6v to both a A and F terminals, ground the case. Or, with the belt on, engine running at speed, jump the F terminal to the A terminal. You should get unregulated voltage at the A terminal. Just don't test for too long and overheat the generator.

2. With the gen mounted, the top terminal is the ground, the one below is Field, back is Arm.

3. No need for further polarization. If you got a small spark when you touched the field wire to the bat terminal, it is polarized.

FYI, something you need to keep in mind, if you don't already know, your gen is a type "B" generator. The field winding is grounded inside the generator and is conncted to the armature circut inside the regulator. That makes a difference in polarizing and testing, and the type regulator used.
 
Wire continuity is good on ground,arm,field wires..VR case is grounded and verified...i get same volts at battery with motor off or running medium throttle. The ammeter shows discharge when headlights on but other than that the ammeter is steady ZERO.
 
Also ZERO volts between FIELD and ARM studs at generator. No need to motor test the genny i reckon as its putting out nuthin.

Can i be missing something or dkes it sound like genny is deader than hell. Any brush adjustments i can make?
 
(quoted from post at 19:55:41 03/22/18) Also ZERO volts between FIELD and ARM studs at generator. No need to motor test the genny i reckon as its putting out nuthin.

Can i be missing something or dkes it sound like genny is deader than hell. Any brush adjustments i can make?
ero volts between field and arm is normal when battery is low, as that is exactly what the VR contacts do....connect field to arm! While running, try jumper from BATT to ARM and see if you then have charging current & in crease in battery voltage.
 
(quoted from post at 17:01:31 03/22/18)
(quoted from post at 19:55:41 03/22/18) Also ZERO volts between FIELD and ARM studs at generator. No need to motor test the genny i reckon as its putting out nuthin.

Can i be missing something or dkes it sound like genny is deader than hell. Any brush adjustments i can make?
ero volts between field and arm is normal when battery is low, as that is exactly what the VR contacts do....connect field to arm! While running, try jumper from BATT to ARM and see if you then have charging current & in crease in battery voltage.

I will try it and see....the battery is brand new though and shows little over 6volts while turned off...shows same running though.

At this point i would pee on a spark plug if it would help. Im about to run the genny motor test...if this fails then the genny is dead i assume
 

Wow....the genny motor test passed...generator spins strong when ARM and FIELD connected to battery negative post!

Im missing something
 
Ok...the genny spin test
passed with flying colors...i
did as suggested and while
running jumped the ARM to BAT
and there was a change....the
Ammeter went to MINUS 30 so i
quickly disconnected.
 
(quoted from post at 20:43:21 03/22/18) Ok...the genny spin test
passed with flying colors...i
did as suggested and while
running jumped the ARM to BAT
and there was a change....the
Ammeter went to MINUS 30 so i
quickly disconnected.
K, so what did battery voltage do during this -30A time period?
 

Dont know...i panicked when ammeter pegged at minus 30....im working on it now and will jump arm to bat at VR again and check volts at battery if that doesnt fry anything
 

Ok...did it again....when jumping ARM to BAT at VR the ammeter dropped to minus 30 and the volt meter across the battery didnt move any....steady at about 6.5 volts. Battery is new
 
(quoted from post at 21:16:27 03/22/18)
Ok...did it again....when jumping ARM to BAT at VR the ammeter dropped to minus 30 and the volt meter across the battery didnt move any....steady at about 6.5 volts. Battery is new
f ammeter were wired backwards, I would have expected the voltage to go up. If ammeter wired correctly, I would have expected the 30A drain to have lowered the battery voltage at least some. I'll think on it.
 

Thanks for the help....i will add i checked volts at genny as you sugessted fkr someone else....pos lead of meter on ground and negative at ARM post at rear of genny....results ZERO....its puzzeling as the genny motored but acting like its not putting anything out.

Dont kniw if that indicates wiring issue, polarization issue or what. Its over my head...all i knkw to do is go ahead and rewire the three leads from the genny.

I will add one oddity....i read theres a post on the top of gen barrell when mounted....i have two post fkr Field and Ground on barrell at bottom side when mounted. Then i have the Arm poat at the rear. I assume its a B genny as its sulposed to be since the Ford Tractor repair place in town installed that genny 10 years ago. I do knkw i had it charging after rewire i did 2 years ago but that was short lived.

I have NO faith in the local Ford tractor repair as they fried system which is why it needed a replacement genny back then. Theres NO markings on the genny
 
(quoted from post at 22:37:14 03/22/18)
Thanks for the help....i will add i checked volts at genny as you sugessted fkr someone else....pos lead of meter on ground and negative at ARM post at rear of genny....results ZERO....its puzzeling as the genny motored but acting like its not putting anything out.

Dont kniw if that indicates wiring issue, polarization issue or what. Its over my head...all i knkw to do is go ahead and rewire the three leads from the genny.

I will add one oddity....i read theres a post on the top of gen barrell when mounted....i have two post fkr Field and Ground on barrell at bottom side when mounted. Then i have the Arm poat at the rear. I assume its a B genny as its sulposed to be since the Ford Tractor repair place in town installed that genny 10 years ago. I do knkw i had it charging after rewire i did 2 years ago but that was short lived.

I have NO faith in the local Ford tractor repair as they fried system which is why it needed a replacement genny back then. Theres NO markings on the genny
ne of the two barrel terminals will have an insulator washer/feed-thru and the other will not. The insulated terminal is the Field. The terminal without insulator is the Ground & makes full contact with the metal barrel. I expect that the A-F-B terminals of the regulator are clearly marked and that the Field is the middle of the 3 terminals??
 
(quoted from post at 02:15:49 03/23/18)
(quoted from post at 22:37:14 03/22/18)
Thanks for the help....i will add i checked volts at genny as you sugessted fkr someone else....pos lead of meter on ground and negative at ARM post at rear of genny....results ZERO....its puzzeling as the genny motored but acting like its not putting anything out.

Dont kniw if that indicates wiring issue, polarization issue or what. Its over my head...all i knkw to do is go ahead and rewire the three leads from the genny.

I will add one oddity....i read theres a post on the top of gen barrell when mounted....i have two post fkr Field and Ground on barrell at bottom side when mounted. Then i have the Arm poat at the rear. I assume its a B genny as its sulposed to be since the Ford Tractor repair place in town installed that genny 10 years ago. I do knkw i had it charging after rewire i did 2 years ago but that was short lived.

I have NO faith in the local Ford tractor repair as they fried system which is why it needed a replacement genny back then. Theres NO markings on the genny
ne of the two barrel terminals will have an insulator washer/feed-thru and the other will not. The insulated terminal is the Field. The terminal without insulator is the Ground & makes full contact with the metal barrel. I expect that the A-F-B terminals of the regulator are clearly marked and that the Field is the middle of the 3 terminals??

I will be rewiring the generator this evening, but was wondering what the proper way to check the output of a NAA Gen (6v pos ground - B type) with a multimeter. I have the analog meter but not sure i am checking the output at the GEN correctly as it passed the motor test.

1. Do i disconnect all wiring from gen first?
2. where to place the pos and neg leads from the multimeter
3. I assume i set meter to read 10 V for this test
 
Yes...i am wanting to see if the gen is putting out voltage needed independent of the rest of the system. If that's the case then
i assume my problem is in the wiring harness...the gen did motor, but the volt test i tried at the gen showed zero. I am not
confident i am testing the gen correctly with the meter.
 
Remove wires from generator (except ground, if you are sure you have identified ground terminal of gen).
Connect voltmeter, pos to chassis (pos of battery).
Connect neg of voltmeter to generator ARM.
Run engine and you will see only a small output ~ 1 volt.
While running connect a wire from battery neg to generator Field and you should see dramatic increase in voltage, since it is lo-load/open circuit....may be as high as 20 volts! So don't run long at this voltage.
 

1.5 volt output at gen so didn't do the direct connect you mentioned in second test...i had to grind the meter prong into post to get any reading....im ripping the three wire harness out...vleaning the three post at gen and see if that gets the juice flowing.

Glad the gen is putting out like supposed to...the issue has to be in the harness. I got to thinking the checking continuity of each wire didn't do anything if there's a crossing in the harness...that could explain why my old VR melted
 
(quoted from post at 15:38:20 03/23/18)
I will post back once done in little while

Incredible....the gen passed the spin and voltage output (1.5 volts)...i verified wire connections with correct posts on gen...insulated barrel is field..non insulated barrel post is ground....read larger post is ARM....I REWIRED, BRASS brushed all post and filed the nuts for good contacts...tge VR is new and field has been polarized....points and condenser new....battery new....6 V pos ground and starter relay contacts verified....wire continuity to ignition and a meter verified.

Battery is at 6.5 volts when not running...still at 6.5 running.

It simply isn't charging...frustrating to say least.

I'm gonna run this new battery into the groubd...charge it when needed....jump it off with my truck if dead...and when it doesn't run anymore....set it on fire and buy a John Deere.

I do appreciate the help...but damn...
 
(quoted from post at 23:35:54 03/23/18)
(quoted from post at 15:38:20 03/23/18)
I will post back once done in little while

Incredible....the gen passed the spin and voltage output (1.5 volts)...i verified wire connections with correct posts on gen...insulated barrel is field..non insulated barrel post is ground....read larger post is ARM....I REWIRED, BRASS brushed all post and filed the nuts for good contacts...tge VR is new and field has been polarized....points and condenser new....battery new....6 V pos ground and starter relay contacts verified....wire continuity to ignition and a meter verified.

Battery is at 6.5 volts when not running...still at 6.5 running.

It simply isn't charging...frustrating to say least.

I'm gonna run this new battery into the groubd...charge it when needed....jump it off with my truck if dead...and when it doesn't run anymore....set it on fire and buy a John Deere.

I do appreciate the help...but damn...
ell, I never give up! Old JDs had generators & electro-mechanical VRs too. By skipping the part of my instructions to apply battery voltage to Field of gen, we failed to finally determine whether or not gen was OK or not. Most likely a VR problem, but your -30A situation is odd. If all wiring is correct & you have the correct replacement regulator and it is in fact a "B"- type generator, then you can make it charge by having jumpers ready & starting it & jumpering BATT to ARM & then ARM to Field. With both jumpers in place and at speed you should definitely see a charge indication, both in battery voltage and ammeter reading. The two jumpers are doing exactly what the VR does when demanding full charge.
 
(quoted from post at 21:17:14 03/23/18)
(quoted from post at 23:35:54 03/23/18)
(quoted from post at 15:38:20 03/23/18)
I will post back once done in little while

Incredible....the gen passed the spin and voltage output (1.5 volts)...i verified wire connections with correct posts on gen...insulated barrel is field..non insulated barrel post is ground....read larger post is ARM....I REWIRED, BRASS brushed all post and filed the nuts for good contacts...tge VR is new and field has been polarized....points and condenser new....battery new....6 V pos ground and starter relay contacts verified....wire continuity to ignition and a meter verified.

Battery is at 6.5 volts when not running...still at 6.5 running.

It simply isn't charging...frustrating to say least.

I'm gonna run this new battery into the groubd...charge it when needed....jump it off with my truck if dead...and when it doesn't run anymore....set it on fire and buy a John Deere.

I do appreciate the help...but damn...
ell, I never give up! Old JDs had generators & electro-mechanical VRs too. By skipping the part of my instructions to apply battery voltage to Field of gen, we failed to finally determine whether or not gen was OK or not. Most likely a VR problem, but your -30A situation is odd. If all wiring is correct & you have the correct replacement regulator and it is in fact a "B"- type generator, then you can make it charge by having jumpers ready & starting it & jumpering BATT to ARM & then ARM to Field. With both jumpers in place and at speed you should definitely see a charge indication, both in battery voltage and ammeter reading. The two jumpers are doing exactly what the VR does when demanding full charge.

I will try that tomorrow and thanks again for the help...this tractor has had charging issues since I've had it....2002. Constant work to keep it original seems futile....worse case is I will ride this battery out and keep charging it and when it craters I will be swapping to 12V....i kick myself for not doing it this go round.
 
(quoted from post at 00:53:21 03/27/18) What Texas town are you near, TX?

I'm near Richmond, TX

by the way...i ran the tractor for about 12 hours this past weekend with no issues other than the charging...now I can work on it without having all that work waiting. It pulled the box blade without a pickup.

I will get it back to my shop and complete the diagnostics on the genny and advise. If it's bad I will see if they can rebuild cheap....otherwise I will keep charge on battery and use it til this bttry craters and then make the 12 volt change.
 
Will try to keep watch for your results. I'm about 300 miles north, but have visited relatives in Rosenberg.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top