12V Conversion questions

[Ramon]

I am looking at a Farmall 100 tractor and when I checked it while it was running at idle, the ammeter showed the tractor was not charging. The gent selling it told me that it was because when he did the 12V conversion, he didn't change the pulley. He said that it's no big deal and just to make sure that I get the engine running hot and it will start charging normally. First of all, is there really a different pulley used for the 12V system vs the 6V system and secondly, will cranking up the engine and running for a while really make it it charge correctly? Thanks

 

[Soundguy]

Lots of things to consider.

First. Is it an ammeter or a volt meter.

Most of these antique tractors use an ammtere, and have it wired to show net discharge or charge to the battery. Onc ethe battery is charged.. the needle should be nearly at zero... only showing the 1-3 amps of ignition draw. On an old ammeter.. 1-3 amps may barely be a deflection on the needle.

When folks swap over to an alternator a few new problems arise. 1) alternators usually don't charge under 400-500 rpm. If it is a self exciting alternator.. it may need an engine rpm of up to 1600 to 1800 rpm before it 'excites'. Once excited.. it should charge down to about 500-600 rpm. Under that and it kicks out. Also keep in mind that at low rpm.. the alternator won't be an efficient charger either.. an alternator at 600 rpm won't be charging to full potential. Here's the problem./ Most of our antique tractors tach out pretty quickly. I've seen units that don't even run 1500 rpm, and idle less than 500 rpm. To make up for this you can get a smaller pulley. This pulley make sthe alternaot run at higher than engine rpm.

Another thing to so is get a 3 wire alternator.. not a 1 wire alternator. The 1 wire jobs ar ethe ones that need to be run up to a higher rpm to start to charge.. the 3 wire jobs can be externally excited, and will start charging as soon as excited. For instance.. the gm delco 10-SI alternator comes in both 1 wire and 3 wire versions.. bnoth have internal regulation. The one wire is as i described.. 1 wire to the battery.. lotsa rpm and you are ready to go untill the rpm drops down past 500 or so. The 3 wire jobs have the wire to the battery, and then the p2 terminal tied to the battery stud.. this is a 'sense' line for the VR. P1 is then hooked up to a toggle switch. After you start the tractor and idle it up to a point the alternator can charge.. hit the momentary switch and the alternator kicks to life. There are other ways to do it other than a switch. A diode will work, or even a marker lamp from the ignition switch to the p1.. this gives it some excite power.. but doesn't let the alternator backfeed the ignition. The diode version is elegant.. but some don't like to get into electronics that much.

The extra switch is fool proof and easy.

Probably what the guy has is one that needs to be tached out to start chargeing. That or the ammeter/voltmeter isn't hooked up correctly.

If ya need any more info let me know.

Soundguy

 

[upgw]

A buddy of mine did a 12-v conversion on a Ford NAA. He said he had to rev way up to 'excite the alternator' then it would charge normally. I'll say this, the 6V starter really cranks on 12V!! My 130 barely turns over with the 6V system.

- Patrick

 

[Ledgemere Farm]

My Farmall 200 has charging issues. I don't run it enough to get the generator to really charge much. I don't even know if it works. The ammeter, I think, is broken. I put on a new regulator, but haven't got something right. Usually, my battery is dead, so I park it on a hill and coast it down in 2nd gear then pop the clutch. works every time.

 

[Ramon]

Wow Soundguy, that was a huge amount of information and pretty concise. At the end of the day, is it really a big deal to have to crank the throttle up a bit to get the system charging? Do most people just live with it or in the long run, do most people fix the issue. Most of the time when I crank up my tractors, I use them at full throttle in low gears (such as mowing or plowing) but then again, perhaps my battery will go dead the few times I don't? What does everyone think? By the way Patrick, I have a 6V on my Cub and it definitely has a tough time. It's nice that it's original(and I love original) , but when it comes to cranking it up in the cold of winter to get my car out of the snow, I'll vote for the 12v.

 

[Soundguy]

Over on the ytmag ford N-board, about half of our questions come from charging issues.. and it is pretty evenly divided on those that use alternators. ( 3 wire vs 1 wire ).

Most of the nubies go for the 1 wire jobs for the -easy- setup. Most of the learn'd folks go 3 wire.

What it comes down to is yes.. At some point while you mow you are probably at enough rpm to get the alternator going.. but maybee not. On our N's for instance... 540 pto rpm is only 1500 engine rpm... Not all the 1 wire jobs will kick in at that rpm.. some need 1800 or so. Some don't like to jazz the cold engine that high to get it to charge.. and instead wait till it warms up to surge it.. then all is ok.. unless your battery is dead.. and you had to jump it.. etc.. in which case.. there is no power for the ignition till the alt kicks in.. if you pull the jumper cables off. The 3 wire job is really much better.. easier on all involved.. and not hard to hook up.. and if you are only idling the tractor around.. it is deffinately the way to go. For instance.. my parade queen 1946 2n is just used to drive around my neighborhood and hit a few shows... I never rev her up much.. I'm glad I have a 3 wire job on there.

For the other poster that installed a regulator.. do you have a generator? If so.. you may need to polarize the system.. and the correct method of polarization will depend on your genny field setup.. ( a-circuit or b-circuit). You cutout may not be closing if it isn't polarized. Also.. Does that tractor have a magneto? Otherwise I'm guessing it has a reeeeal good genny that makes some voltage at low rpm for the ignition ( some of our N gennies will do that ).. or there is some residual battery power for the ignition.. but just not enough for the starter.

Soundguy

 

[upgw]

My 130 charges at 15+ amps for the entire time I'm dragging a harrow, which is about 1 hour per week. Enough charge to boil some water out of the battery, yet it always seems dead. Perhaps the battery is bad, I don't know how old it is. The 'working restoration' is about 10 years old, I think the blown engine was first revived in 1994. It looks like the original wiring and switches were removed and only a single push/pull switch remains. Something discharges the battery if I leave it connected, so I have to pull a terminal at shutdown. I suspect this is a result of the current wiring setup.

I'll probably keep it the original 6V and put up the the slow cranking.

- Patrick

 

[Soundguy]

It is very possibile that the field winding in the alternator is pulling it down. Try tracing it and putting it on a seperate switch to isolate it. Also.. do you have a spare battery to throw in to check the charge status... perhaps that battery is old like you suspect.. and causing the dead battery.. and prolonged charge rate.

Soundguy

 

[AndyM]

<font color="blue"> Another thing to so is get a 3 wire alternator.. not a 1 wire alternator. The 1 wire jobs ar ethe ones that need to be run up to a higher rpm to start to charge.. the 3 wire jobs can be externally excited, and will start charging as soon as excited. For instance.. the gm delco 10-SI alternator comes in both 1 wire and 3 wire versions.. bnoth have internal regulation. The one wire is as i described.. 1 wire to the battery.. lotsa rpm and you are ready to go untill the rpm drops down past 500 or so. The 3 wire jobs have the wire to the battery, and then the p2 terminal tied to the battery stud.. this is a 'sense' line for the VR. P1 is then hooked up to a toggle switch. After you start the tractor and idle it up to a point the alternator can charge.. hit the momentary switch and the alternator kicks to life. There are other ways to do it other than a switch. A diode will work, or even a marker lamp from the ignition switch to the p1.. this gives it some excite power.. but doesn't let the alternator backfeed the ignition. The diode version is elegant.. but some don't like to get into electronics that much.

The extra switch is fool proof and easy. </font>

I went with the three wire alternator on the 8N.
I have it wired up like this... (see attached picture)

You can avoid the separate switch, or diode, or marker light, simply by installing a key switch with an "accessory" position.
The red wire that runs to the alternator is hooked up to the key switch on the "accessory" terminal on the key switch. The yellow wire coming from the starter solinoid is hooked to the "battery" terminal on the key switch, and the wire coming from the distributor is attached to the "ignition" terminal on the key switch.

I'm certainly not an electronics expert by any means, but I'm good at following directions, even if I don't quite understand them. Someone here on TBN told me to hook it up this way last year, but I can't find the post now. It seems nice and simple, and easy to hook up, and I haven't had a problem with it since I hooked it up that way. Maybe someone else can explain WHY it works that way! /forums/images/graemlins/smirk.gif

 

[upgw]

It's still got the generator... I'm guessing the old (missing) switch turned something off that is now hard-wired on. Any ideas?

- P

 

[Soundguy]

Simple.. it is a multi pole switch with one pole being momentary... in effect 2 switches. yet having seperate contacts as if 3 switches. that's how the isolation occours for the alternator. as for the solenoid hookup.. that is only true if you change out the solenoid on the 8n. The oem ford solenoid was 3 terminal, and the coil was internally hot.. the third terminal merely grounded the solenoild coil via the big tranny neutral interlocked thumb sized switch in the tranny top cover. A newer isolated 4 terminal relay is needed for the starter combo switch hookup.

Also.. we ( guys ont he ytmag board N-forum ) are a bit of purists... and generally like to keep our tractors as close to oem as possible. That usually means that we like to keep our oem one position ignition switch. And also, many do not convert to 12v unless they have a 12v accessory or implement. Also.. there are at least 2 alternator conversions out for the early fords.. one used an older alternator and a regulator.. the other is a newer unit.. 3 wire setup.. and is still serviced by NH.

Soundguy

 

[Soundguy]

Did you get the correct regulator? Sounds like no.

Gennies come in two basic types.. a circuit.. and b circuit.

Both have a cutout relay that keeps the genny from draining your battery when not charging. Both regulators need to be polarized to set the cutout relay.

Here is where they differ.. an A circuit genny has a field coil that is internally hot.. and the genny vibrating contact provides ground to the genny field.. thus letting it charge. Therefore on an a-circuit genny.. you can jumper the field terminal on the genny to ground and get max charge.. this is called full-fielding it.

On a b-circuit genny.. the field winding is internally grounded, and the regulator provides field current via the vibrating contact. To check a b-circuit generator, you jumper battery to field to giv max current to the field ( bypasses vibrating contacts ).. and that full fields the genny.. producing max charge.

Charging at 15 amps sounds like max charge for an early genny. The genny on my JD maxes at 7amps.. and the genny on my cub maxes at 11-14 amps.. while the genny on my fords max at 11 amps for the old b-circuit 3rd brush adjustable1 wire jobs.. to 20 amps for the later a and b circuit 3 wire jobs.

Check your manual to find out what type of genny you have. My 1966 IH cub happens to have an early 12v a-circuit genny.

If you know what type of genny you have you can test it easilly. While running, disconnect the field connection at the genny. Check with a vom between ground and the field terminal.. if you read any voltage.. it is probably an a-circuit. In which case you can jumper it to ground to get max charge. If you read no voltage... it may be a b-circuit.. in which case you could jumper it to the battery hot for max charge.

Keep in mind that these gennies won't like to be full fielded for any protracted length of time.. just enough to test.

Usually when I see a genny putting out max after a VR swap.. it is an a-circuit that has a wrong regulator, and it is grounding the field.. or it is that the insulation is damaged at the field terminal letting it ground out.. or something inthe wireing is shorted letting it ground.

The symptoms you mentioned of the battery dieing are consistant with an incorrect VR.. or one that has the cutout contacts either welded together due to not polarizing it, or just not closing because it was not polarized.
To polarize *many* but not all a circuit regulators and gennies.. jumper bat to armature ( may be called genny on old vr's ) for a second.. might make a spark.. this sets the field poles and determines polarity of the charge and polarizes the cutout relay. ( yes.. most gennies can be repolarized to charge either negative or positive ground.. but you have to watch out for the regulators.. the old ones were'nt isolated.. so best to leave them how they were from oem. )

Most b circuit regs and gennies polarize by jumpering batt to field for a second.

Do these polarizations with engine NOT running.. and caution.. polarizing wrong almost always destroys the regulator... That means that if you jumper batt to field on an acircuit regulator.. you just lost 30-40 bucks in a puff of smoke.

Any time a genny has been rebuilt.. or a new regulator has been added.. or if either has been removed.. or the genny has been dropped or banged with a hammer.. or if it has set a protracted amount of time.. it is best to repolarize the system.

Soundguy

 

[Soundguy]

I'll add one more thing.. many of the old gennerator systems incorporated resistors of different values into the ignition and light switches. This was to 'tickle' the generator into putting out more power when the lights were on.. and less when it was only the ignition running...

You will need an oem schematic of your tractor to determine this.. and also check to see that you still have the oem genenrator.. etc.

lots of things get changed in 60 years..

Soundguy

 

[nobull1]

Quote
Also.. we ( guys ont he ytmag board N-forum ) are a bit of purists... and generally like to keep our tractors as close to oem as possible. That usually means that we like to keep our oem one position ignition switch. And also, many do not convert to 12v unless they have a 12v accessory or implement.

Soundguy
I have been over to a few of the vintage tractor sites and wonder why people convert to 12 v.On my 54 cub half of the parts for the generator were missing from years of people working on it /forums/images/graemlins/frown.gif.So we used to just charge the battery and could use it for a month or so before it went dead,not a good idea but that is what we did.When I decided to get the charging system working I went to alternator repair shop and had them build me a alternator that put out 6 volts,actually about 7 volts if I remember correct.This is a easy thing to do for them and it means your whole system is still original except for the alternator.I used a one wire and have to rev to about 1200 rpm to excite but can drop down to 400 and still charge.The people that built the alternator knew of the exciting problem and just put a different regulator in that required less rpm. I am amazed that people don't do this instead of switching to 12.The starter still works on 6 volt instead of 12 which has to be easier on it and no wiring to do. I installed the above type alternator about 6 years ago and has never missed a beat.

 

[Soundguy]

Yes.. I've seen 6v alternaots custom built.. as well as positive ground alternators. I've also seen generators from newer 12v tractors used in place of the oem 6v genny.. or even having the old 6v genny re-wound 12v.

As for the alternaotos.. I don't like 1 wire jobs.. it is too much of a cob/hack. Voltage regulators are easy to come by and install... The mid 80's hitatchi alternator on my yanmar 1700 uses a common 10 dollar chrysler vreg...

Also.. it is soooooooo easy to use a 3 wire and build in an exciter circuit... lotsa ways to do it.

Most guys that convert from a 6v genny don't go to a 6v alternaotr... they go ahead an go to 12 if they get an alternator. Most 6v gennies will be right behind a 6v alternator in amps produced.. and the genny will produce at a lower rpm using an old vibrating contact vreg.. than the 6v alternator using a low rpm regulator. A smaller than oem pulley on the alternator does offset this difference quite a bit, making them about even. On the flip side.. gennies are more tolerant of being hooked up backwards.. whereas alternators are NOT reverse current tolerant. Add to that that gennies can be polarized as either negative or positive ground, and back and forth... thet's pretty decent. Besides.. For gas jobs.. I like positive ground better due to the edison effect and spark plugs.

Soundguy

 

[nobull1]

I would agree that the three wire has the potential to be a better alternator.When I got mine it was a one wire and that never came up about using a three wire.For the life of me I can't remember how they did it but it took only a couple of mins.and could be changed to 12 v for about 30.00 if wanted or required.The funny thing is a lot of the vintage tractor people, like you have said want to stay as much original as possible.In 7 or 8 years of following different sites I never seen anyone just upgrade to a 6 v alternator.This is a easy upgrade no wiring and just a bracket to make for mounting.The reason I posted was only really to ask why this was not done as it is so simple and you get low repair technology .Can't argue with anything you say in regards to tractor charging systems /forums/images/graemlins/grin.gif

 

[RobertN]

The selection of one-wire altenators is actually not bad. Just gotta look in a wider area. Rock Crawlers had this issue too. You get a Jeep out on Rubicon idling all day, 'cause that is about as fast as you can go over the rocks. So, they do not charge...

Some folks started working things out so they have one wire systems for ease of installation, and the ability to charge at very low rpm. It's another niche /forums/images/graemlins/smile.gif Stuff is availble through 4wd shops/magazines.

They do tend to put out more than we might need on tractors though. Some are rather beefy 100-150A jobbers, for good recharge after heavy winching or running accessories.

Premier even makes a lowrpm charge altenator with stuff built in to make it a stick-welder with 110v accesory plugs too /forums/images/graemlins/cool.gif
How about that for that field repair you gotta make /forums/images/graemlins/wink.gif My B-in-law has one on his Jeep; it is pretty dang cool!

 

[Soundguy]

</font><font color="blue" class="small">( Some folks started working things out so they have one wire systems for ease of installation )</font>

Choosing a 1 wire job over a 3 wire job for 'ease of instalation' is like choosing masking tape over duct tape. The 'real' work comes in mounting the alternator... Hooking up two additional wires ( one simply jumpered between 2 terminals on the alternator ) isn't a big deal.. or at least.. shouldn't be.

Soundguy

 

[Soundguy]

</font><font color="blue" class="small">( it took only a couple of mins.and could be changed to 12 v for about 30.00 if wanted or required )</font>

Might have been something as simple as a change from parallelled to series winding connections.

And most of us vintage tractor purists would rather have a 6v genny than a 6v alternaot on our machines. If we go alternator.. might as well go 12v.

Besides.. gennies are pretty easy to maintain.. and not too much to go wrong. I can pull a genny apart, change brushes dress the mica on the com'tator and re-bush in a few minutes on the bench.. and unless the field or armature winding is bad.. that's all there is to the internals. An alternaot is another ball of wax.. Internal vr's diode packs.. etc... not very user serviceable compaired tot he genny.. which more or less just consumes brushes every 20 years...

Soundguy

 

[upgw]

Per the manual, looks like I have an 'A' circuit generator. Two wires from the generator to the regulator. Here's a neat page on another guy's 130, it pretty much sounds like mine starting:

http://www.oldoakfarmalls.com/130Page.htm

I was up at tractor supply and while they were out of 6V batteries, they did have 8 volt ones... strange.

Per the service manual, the missing fuse and switch was all for the lights, which it doesn't have any longer, so perhaps the current wiring is correct, seems like something is going on in the regulator.

- Patrick