No voltage Early 8N model

I am mechanically inclined, totally out to lunch when it comes to electrical. Tractor will not start. Took off front mount distributor, cleaned points, still not starting. Noticed that amp meter did not move to discharge when key was turned on as it did in the past. Traced electrical charge through switch, resistor and then to what appears to be voltage regulator on right side of tractor firewall. Hot on the input wire, but then I lost it after that. Only appears to be two wires on that unit on that tractor. The wire on the right side of regulator was hot, the wire on the left was not. So here are the question(s) 1. Will the electrical move through the regulator without turning the starter (I suspect yes, but want to verify). 2. If the regulator is bad, will that cause the amp meter not to register a discharge? 3) Are there more than two wires on that regulator to check?. 4) any other ideas on how to check the electrical past that point? Thanks in advance for your answers. You have been very helpful in the past. Ron Petterson

Post some pictures for us.. some things don't add up.

2 wire regulator?

no voltage? no voltage where? Does your starter turn when you press the big trans mounted thumb button?

If the starter turns, then try this. jumper from battery hot to the top of the coil and see if it will start. if yes, then trace the wire back from the coil to the resistor block, to the switch, to the lower terminal of the resistor block, etc.

Hi Ron, like Sonudguy said a picture or two would be helpful, but has your tractor been converted to 12 volts? We need to know that. It sounds like you got lost tracing the wires. There should be a wire (originaly red) going from the ballast resistor to the coil. Also what are you using to trace the voltage? A test light isn't always the best thing to use.

I am using a volt meter, not light. I did get to the top of the distributor and with the switch on, I get a ,6 volt reading, so I guess cleaning the points did not work this time. Going to get new points and try that. I was just confused since the amp guage did not move when the switch turned on or cranking the engine. But getting juice to the distributor seems to tell me its inside that thing again. If that tractor sits 3-4 weeks, its ckean the points or it wont start. Been thinking about electronic ignition, but some say those work and some say they are not good for front mount 8n distributor tractors. Thanks for your help. Any other ideas would be helfful. Hard to do pictures as it is in shed without lighting, so pictures would be very dark. Ron

" I get a ,6 volt reading,"

Exactly what did you get? At 6.03 volts, your battery is only 25% charged.


" If that tractor sits 3-4 weeks, its ckean the points or it wont start. "

How are you cleaning the points?

If you are using a file or sandpaper, you've removed the thin metallic coating on them and you will be having to clean them every 3 weeks or so.

Time for a replacement set of points.

See tips 66, 67 & 68.
75 Tips

I will look closer at regulator. Will take flash light and look up under "hood" through the door for filling gas tank. Probably some more wires up under the cover that are hard to see. I am getting volts to the top wire on the front mount distributor, so I think its those points that need to be replaced. Cleaning may not have worked.

Yes the tractor turn over, just not starting. I am aldo going to pull spark plug wire and check for spark there.

Whats your thoughts on electronic ignition for front mount distributors?

You CAN go ei, but if you do, I would suggest the kit that replaces the square coil with a cap so that you can use a round coil.

Re check those points. Try that jumper wire first.

I have to agree with Bruce. Both of my tractors can sit for months and start right up. Both are 6 volt, one is a front mount like yours and the other is a NAA with the distributor on the side of the block. None have E.I. If you think you need E.I. consider it a band aid that's covering something else.

Bruce, So a 6 volt system will show 24 volts in the system? How? If it were 25% charged, would it not be sluggish turning over?
I am using expensive points. If I crank it over and it only sits a week or so, starts every time. Will do that for months. Let it sit 3-4 weeks and the points have to be cleaned. Been using fine emory cloth opening the points, placing that in between, closing the points and pulling it through once or twice. Works fine and usually starts good until another 3-4 week no run period and repeat operation. Its almost like the system has a weak electrical charge that is present in the points, but not strong enough to run down the battery that is burning the points while it sits. I know that is not happening, but strange it does not happen until an extended no run period.

a fully charged 6 volt battery should actually be ~ 6.35 volts.

" If it were 25% charged, would it not be sluggish turning over?"

Yes, at 25%, but the issue is how much voltage is left for the ignition. You can have a battery low enough to turn the starter and have nothing left to fire the plugs.


" Been using fine emory cloth" which removes the metallic coating on the points t a bit slower rate than a file.


" So a 6 volt system will show 24 volts in the system? "

I hope that was meant as a joke.

I suggested that you check the actual voltage; " a 6v reading" does not tell you much. If you do not know what it is supposed to be, then ask. Surely you know it's not supposed to be 24 volts. As HFJ said, fully charged is 6.35 volts.


Once again, you could easily have a weak battery. If you want to install EI on the tractor, that will resolve your problem of cleaning points. But unlike points that will fire on a weak battery, EI will not. So if you have a non-starting tractor on points, you could easily have a non-starting tractor on EI because your battery is not holding a charge.
75 Tips

HiYa Ron-
You are asking and getting good advice from two of the most knowledgeable electrical experts on this forum -Soundguy and Bruce(VA)so take heed. By ?early 8N? we will assume you have a front mount distributor, and that is what matters for now. Equally important as well is we need to know if 6V or 12V. The original Ford electrical systems were 6-VOLTS/POSITIVE GROUND, all vehicles, not just the tractors. Many have been switched over to 12V/NEG GRN and there's nothing wrong with that. Either system requires it to be wired correctly and that is where many if not most problems occur. It sounds like you have some boogered up wiring so let?s go thru the basics. The early 8N setup required a 3-wire generator, a voltage regulator, a ballast resistor, an ammeter, starter switch button, 6V battery, 6V coil, an ignition switch, and all the wiring connected correctly. If you see a round-can unit on the rear dash/steering box, it is a cutout circuit ?used from post s/n 9N-12500 until the end of 2N production. It has 3-wires terminals. The 8N Voltage Regulator has 4 Wires, not 2. There is a terminal for: ARM; BAT; FLD; and a GRN terminal. The original 8N voltage regulators were supplied by AUTO-LITE (see picture), and as are all 8N VR?s mounted on the upper RH rear dash panel, near the oil pressure gauge. The newer aftermarket VR?s (see picture) are a bit different than the originals, but, still have 4-wire connections. If you have a VR, and only find two wires connected, I?d start there. You say you are using a VOM ?that?s good, a test light won?t tell you what you want to know, and most require power to be effective. A meter can be used as a continuity tester and requires no power to a circuit, but you are going to be working in DCV and OHMS (AMPERAGE). It is important that you have your VOM settings correct when checking either or. A dead battery isn?t going to help matters so first up is to get the battery tested and if it?s bad, replace it with the correct style. No Deep Cycle, RV, golf cart units ?GRP-1 6V, GRP 25 or 35 12V. The battery must sustain a full charge under load to be effective. A good starter/alternator shop or local auto parts store can bench test it very easily. Next, as mentioned, cleaning the points via sandpaper or a file or anything else abrasive is a no-no. 99.98% of all non-starting issues are electrically related, usually poor/bad/incorrect wiring. That being said, the first test when not starting, other than a good battery, would be to check for fuel flow at the carb. If fuel flow is sufficient, move on to the spark test. Leave distributor on and alone for now. Take your VOM, set function to VDC, and ensure the range isn?t mV or you?ll get crazy readings. Power off, take a reading of what the battery voltage is static and make a note. Take one meter probe, it doesn?t matter which one, polarity has no effect here, and probe the LH terminal connection on the ballast resistor. That is where the coil wire connects to. If it isn?t further investigation is needed before proceeding. If it?s okay, then turn the key switch ON, but don?t start tractor switch, and take the other meter probe and touch ground anywhere. You should see VDC identical to the battery voltage with points open, half that with points closed. If good, move on to top of the square can ignition coil terminal post, there?s only one, and repeat the test. If results are the same, voltage to the coil is good, the problem is likely in the distributor and/or a bad coil. NO VDC readings at the resistor post or the coil post indicate the problem is likely in the resistor, coil, ignition switch, or the wiring of any combination. The generator and VR are part of the charging system not the ignition system, however goobered-up wiring can result in any scenario. You need to use your essential manuals for help ?the I&T F-O4 Manual and the 39-53 MPC especially. Do not buy any new parts and start replacing until old ones determined to be failures. Finally, do not determine wiring by the color of the wires. The original harness is probably long gone or faded beyond recognition. New, exact-as-original wiring harnesses are available like the one shown in Steve Dabrowski's restored 1948 8N with an Auto-Lite VR below. Colors do not conduct electrons -always perform continuity to verify.

ORIGINAL FORD 8N ?AUTO-LITE? VOLTAGE REGULATOR:

NEWER/AFTERMARKET 8N VOLTAGE REGULATORS:

WIRING DIAGRAMS FOR 8N w/FRONT MOUNT:

Tim *PloughNman* Daley(MI)

Thank you everyone for your help. As always you are a big help. (And no the question about 6,volts being 25% charge was not a joke since batteries I have taken to auto stores to check have shown volts lower than 12 for cars and cranking amp less than max, ie 12 volt battery with 8 volts).As far as I can determine so far is the problem is in the coil/distributor. I am getting an electrical reading all the way to the coil wire, basically the same coming from the switch. That indicates to me the switch, ballast and anything else is ok. The battery is charged and I get a good crank when trying to start. Could be the amp meter on the tractor is faulty and that is why it no longer shows discharge when switch is on or cranking. My next step is to check coil and replace points. If that wont work, then I will be back for more ideas. The amp meter issue is what has thrown me a new wrinkle in a repeating issue.

At 6.03 V, your 6-Volt battery is only about 25% charged. Those 12-Volt batteries that you haul to the store with voltages well under 12 V are badly discharged and at the point where the life of the battery is damaged by the discharge.

The useful charge range of a 6-Volt battery is:
6.32 100%
6.22 75%
6.12 50%
6.03 25%
5.95 0%

https://batteryuniversity.com/index.php/learn/article/how_to_measure_state_of_charge

It's healthiest for your battery to keep the charge near the top.

I recommend fully charging your battery before you try to start the tractor again.

I kind of doubt that your ammeter has died at exactly the same time as you are seeing what might be ignition problems. Since this is an early 8N, it should have a front mount distributor.

1) If you measure from the top nut on the coil to ground, does the voltage measured change between battery voltage and about half or two-thirds that when you crank the engine?
2) If not, do you have the OEM resistor installed? (If there is no resistor, the voltage will stay closer to the battery voltage.)

" As far as I can determine so far is the problem is in the coil/distributor. "

Go ahead and keep chasing that.

You have yet to determine if you have a good battery.

If you want to start tossing parts at it, it's your money and time.


" And no the question about 6,volts being 25% charge was not a joke since batteries I have taken to auto stores to check have shown volts lower than 12 for cars and cranking amp less than max, ie 12 volt battery with 8 volts)"

Thank you for making it perfectly clear that you do not understand what I'm telling you about percent of charge VS a load test.

Tnx Jim.

Maybe he will believe you as he seems to think I'm FOS.

Bruce, please accept my apology. Since written word is difficult to see the real expression, I was not trying to be anything but appreciative. My questions were real, not sarcasm. If you thought I was being an #$% with my 24 volt question, that was real. I am a complete dolt when it comes to electrical stuff, and new electronics today drive me nuts ( more so than I already am).Those who understand that stuff can say something that makes complete sense to them and if they were present, they would see someone looking like a deer in headlights. Completely out to lunch.

So I will take my ignorance back out to the tractor and replace the points and see what happens. If nothing, I will try to find someone who can trace the problem as I see my ignorance can not be fixed.

OK, not a problem.

Maybe I'm not being clear about what I'm trying to get across.

I'm suggesting that you need to do more troubleshooting before you start buying parts.

I don?t know why your tractor isn?t running. Sure, I can make a guess. Actually, I can make a few guesses. And unless I?m lucky, those guesses won?t help you a bit. Don?t guess at the cause of the problem; guessing can get expensive. And leave you breathless chasing every guess.......it could be this, it could be that......just troubleshoot the problem and leave the guess work for buying Lottery tickets. Yes, you could have a points problem. Or a couple of other things.

I might not be able to tell you why your tractor isn?t running but I sure can tell you how to figure it out yourself.

The one way that I found the best results with is to take a systematic, step-by-step approach to solving the problem, working from most likely to least likely. The trick to fixing these tractors (or trouble shooting any piece of equipment) is to be systematic about it. You need to isolate the problem step by step and work from most likely to least likely. Jumping ahead to 'so-and-so said it could be whatever' or just replacing parts usually just wastes your time and your money. I know it did for me.

And the very first thing you need to rule out is a bad battery. You have a voltmeter, so that's all you need at this point.

24 hours after you take the charger off the battery what exact voltage do you see?


If you have 75% or better percent of charge and the starter spins normally, consider the battery good.
75 Tips

Bruce, thanks for your assistance. Hopefully I will not have to bother anyone with electrical issues again. If mechanical, then I would be able to understand most everything written down. So I used the meter and traced the juice to and through the coil. Same reading exiting as entering. Decided to replace the points and bought a kit with new rotor and new condenser. Why not? Been a couple years since those were replaced.

Put it back together and turned the switch. WOW, the amp gauge registered a discharge, Cranked it and started first couple rotations. So either I have a short somewhere in the wiring that I giggled while working on it, or when the points or condenser are bad, they can short out something so the amp meter does not work. I think it must be the first, and if it happens again, i know what to do.I don't know how juice not running through the distributor would have any impact on the amp gauge, nor why I was getting juice to the distributor and through the coil and the amp gauge did not register a discharge with the switch on. Beats me, but its running.