9n Spark Issue

BTHfarms

Member
Hey guys...long time lurker first time poster-

I'm working on my neighbor's 9n 12 volt tractor, I'm mechanical but when it comes to electric I know the basics only.
Here's what happened= Tractor ran fine while discing a pasture and suddenly died out of nowhere as if the key was turned off. Tractor
would not even crank after and neighbor let it sit and bought a new tractor. A couple months go by and he asks if I want to tinker with it
and fix it and we would split the money when sold.

So first I simply cleaned the battery terminals and charged it up and it now cranks like a champ but still no fire. I then found a large
crack on the hidden side of the coil and thought great that could be it....so I ordered a new coil and resistor and still no fire. I opened
the distributor cap and see 2 contact points are very gouged and the other 2 are covered in carbon. So I ordered a new cap and rotor and
still no spark coming out of the distributor cap to plug wires.

I started with my light up wire tester going down the line from the battery to the distributor, have power all the way to points and shaft
of distributor and it went on and off when the points open and close.

The rotor does not light up my tester but i'm not sure if it should? When testing the cap I spin the shaft and when the rotor spins I get
no spark at any of the 4 positions.

I checked the resistance of the coil and at the bottom spring it is low and on the tab that sits on the distributor cap it is much higher
but both the new and old coil test the same so I'm not sure if that is right or maybe I got a bad new coil?

I hope this makes some sense and I can add more info from yall's questions. Pretty much seems I get power to the distributor but can't get
it to the cap and to the plug wires. Any help is much appreciated!
 
Clean or replace the point and gap them at 0.015. You can also pull the cap off and have the coil on and turn it on and open the points by hand being careful not to shock your self. You should both see and hear a spark at the points when you do that and it should be a nice blue/white in color.
 
There is definitely no spark between the points when open. I honestly didn't know they were suppose to arc when open?....sounds like I should order the distributor rebuild kit and replace the points.

Also with the key turned on what voltage should I be getting to the points?
 
what coil did you buy?

what resistor did you buy?

what resistors do you have in line total?

If you found a burnt coil, points replacement should have been a gimmie.
 
As for voltage you should read battery voltage at the wire going into the coil with the point open and with them closed you should read maybe 1 or 2 volts if that much. If you read battery voltage when there open and close then the points are bad and need cleaned or replaced
 
Ok the voltage is the exact same at the top of the coil when points are open and closed. Also there is no spark between the points. I ordered a rebuild kit! I really appreciate it Old! I thought since my test light came on and off at the points they were good....but as I said at electrical im a rookie so glad I posted here!
 
For the coil I bought the 12v front mount from this site but doesnt say a brand.

The resistor I went to oreillys and showed them and they gave me an identical one. There is only one of these in line, is that acceptable?

The coil was badly cracked so Im thinking it overheated/burned up so if that would fry the points like you said looks like the problem is found! I really appreciate the help!
 
I spent 6 years in the navy as an E.T. Which means I was doing electronics's so this simple stuff with tractor is easy for me. Be sure you get a good brand of points not a set form TSC but some form NAPA or O'Reilly's auto parts stores
 
the common 12v coil for a front mount usually measures 2.5 ohms ( though there are reports of lower and higher values too )

If you have the 2.5 ohm coil, and the original style ballast resistor, then that will be an acceptable combination.

If the old coil burnt up, it could have over-current damaged the points.

if you have that corrected, and the new coil and resistor, you should be ok barring other troubles,

you running ok now?
 
Very cool Old....I really appreciate it.

I didn't think O'Reilly would have these and was gonna order online....I will check there which would be great not to have to wait.

If I do order online is there a brand to look for?
 
If you get them on line you want Blue streik As far as the part number form O'Reilly's I could get you that if they have any trouble find it and if they do not have them on hand the can have them by the next day. I also buy my carb kits from O'Reilly's Walker brand #778-505A. And also the sediment bowl gasket. They call it a fuel strainer gasket #398
 
Well I got the point set installed and gapped to .015 and still getting the same voltage at the top of the coil whether the points are open or closed. Also there is no change at the points with my test lamp when I open or close the points, the light stays on. Not sure what to do now
 
Got the new points in and still no luck. Im getting battery voltage to the points. Been trying to adjust the gap to see if anything changes but nope. Set it at .015. Voltage at top of coil stays the same when points are open and closed
 
If no resistor inline to coil, volts will always be the same because you are measuring battery.

If a resistor inline and volts dont change, points aren't closing ( electrically)
 
You need tp figure out where there is a loss of continuity in the circuit from the terminal on top of the coil, through the coil, through the little "spring thingy" under the coil, to the special brass screw inside the distributor that the spring contacts, through the copper strip that connects that terminal to the breaker points, through the breaker points to the breaker plate, to the distributor body.

What does your testlight show when touched to the moveable contact arm, and then to the stationary contact with the points CLOSED?
 
Some points come with a protective coating on them that need to be cleaned off. Pull the ignition wire form the coil and then touch the wire back on with the ignition on. When you do that you should get small spark. No spark means you have an open circuit as in the points are not closing all the way or have that coating on them or you have a bad wire or other such thing
 
There is a resistor inline and its brand new.

So if im measuring around 11.8 at the top of the coil, that should drop when the points close correct? So if its not and I do have power to the points then they aren't closing all the way or correctly right?

If I put my test light on the points should it go off when they close or always stay on?
 
11.8 is low, bat volts should be more like 12.6.

Check across bat hot to chassis, then coil too to chassis. Points open they should be the same. Big yes, and 11.8 at bat, charge here, she's only at 60%.

If 12.6 at bat, and 11.8 at coil top, then points are shorted.
 
Ok Old I did this today. Took coil wire with key on and touched it too the screw on top of the coil....no spark. I swear the points are closing ive been adjusting them a dozen or more times lol. I used a nail file on them before I installed but maybe I should take them out and use something else?
 
So then if the points are in fact closed and you get no spark that means either there coated or you have a bad wire or maybe the copper strip is not hooked up like it should be No spark at the coil say you have an open circuit so power is not getting to the points or if it is getting to the point then are not conducting power to ground a they should be
 
Ok Old I appreciate your continued help, I hope we can figure this out so I can get this thing sold for my neighbor....I haven't been able to work on it the past few days but gonna attack again Mon morn...

Im gonna start by taking points back out and filing them better to make sure the coating is off....then I'm going to try adjusting points again and see what happens. I will report back with the results.
 
I will finally get to try this tomorrow Soundguy. Appreciate the help Ill report with my findings tomorrow.

I know the battery is low I have to charge it or jump off my tractor. Its not old so im hoping it can be saved after all this cranking is over trying to start it
 
Hey Bob I appreciate ur post...i wasnt able to work on the tractor for a few days but getting at it tomorrow.

I have continuety to the points and my test light stays on if they are open or closed....im thinking that means they aren't closed all the way or contacting correctly?

You mention th distrubutor body carrying it from the breaker plate....im a bit confused here where to check. The body itself should turn my light on?
 

You might try and post some pictures it could help the diagnoses from these experts Get pics of the inside and outside and connections of the distributor coil resistor solenoid battery.
Here's how to post them one at a time

Find your picture what I do is copy the picture one at a time and paste it on my desktop

Click on reply to the post. Scroll down Click on upload picture. Click on browse and a new box will appear click on desktop. Scroll down to find your picture. click on picture click open. Click on upload your picture it should appear in the small white box it may take a little bit. Now You can add a description there if you like . Click on continue. Click on Preview this will allow you to see that your picture is there and your comment is there and will allows text correction's If everything is OK scroll down and click submit. Another page will appear. Click return to page or return to forum.

Hope this helps Byron
 
Today I cleaned the points with gas and adjusted them several times. I still get no voltage change with points open or closed. I checked voltage coming from battery through the whole system. Its almost 14 across the battery and before and after the resistor it is about 12.4. Going into the coil it is 12.4ish as well. At the points it is still the same 12.4 with them open or closed, there is no change there or at top of coil when I spin it.

Not sure what to do from here please let me know what yall think
 
Today I cleaned the points with gas and adjusted them several times. I still get no voltage change with points open or closed. I checked voltage coming from battery through the whole system. Its almost 14 across the battery and before and after the resistor it is about 12.4. Going into the coil it is 12.4ish as well. At the points it is still the same 12.4 with them open or closed, there is no change there or at top of coil when I spin it.
Not sure what to do from here please let me know what yall think
 
Ok i charged it and now it is as follows

Today I cleaned the points with gas and adjusted them several times. I still get no voltage change with points open or closed. I checked voltage coming from battery through the whole system. Its almost 14 across the battery and before and after the resistor it is about 12.4. Going into the coil it is 12.4ish as well. At the points it is still the same 12.4 with them open or closed, there is no change there or at top of coil when I spin it.
Not sure what to do from here please let me know what yall think
 
Well, the data is there telling you exactly what the problem is.

You said the battery was 14.

that means with points open, you should have 14v ( battery ) at the top of the coil.

Since you read less, then the points are effectively shorted!

could be the condenser.. could be bad breakers... could be a wire frayed and touching somewhere.

with points open, there should be no current flow and no voltage drop when measured at the top of the coil.

somewhere you are completing the circuit so that the points are not doing anything.. it's like they are already closed.

check out that distribuitor... pull it off if you have to and use a test lamp from distribuitor to chassis. I bet it lights up points open or closed.
 
With the points closed on the top of the coil you should read a whole lot less then battery voltage. Maybe 2-4 volts if the points are closed and making good contact. Sounds like you may have a bad wore or a bad coil
 
Interesting the coil is brand new. I have the old one as well. How should I test them both?

One thing that confuses me is why both points stay hot when open and closed...shouldn't my test light go on and off when they close and open?
 
Ok i think we are getting somewhere soundguy...

I thought 12 was ok at top of coil because of the resistor.

I have tried 2 condensors....i will try both again tomorrow and let you know if the numbers change. Im not sure what breakers your talking about?

I've tried my hardest to find a frayed wire and no luck. What about the little insulator under the screw where the coil spring touches? It seems to be in one piece and ok.

I have the distributor off and today while doing some testing I set it on the steering arm and it sparked. I can touch my test light to the distributor body and it comes on....that cant be right? Some how its getting current, the only place inside I can think would be the condensor wire which isnt touching or maybe back to that insulator? It wouldnt be back up stream of the coil could it?

I sincerely appreciate you sticking with this electrical rookie. I told my neighbor when I took this on that electronic aint my area of expertise.
 
Breaker contacts are the points.

There is no voltage drop across resistors untill current flows.. No current Flo with points open.. Meaning points open, coil top should be battery volts.

The short would not be before the coil, but after. Its in the dizzy. Could be that insulated screw ain't insulated.... Bad breaker plate, etc.somewhere around the condenser, points or their direct location.

Pull condenser out for testing.. Use an ohm meter from dizzy body to locations that should be insulated, like that concave screw. My guess, it ain't insulated.
 
I dont think I put my email in last reply, so I wont get a reply notice if you reply to that post, reply to tho one instead.
 
Yes a test light should go out with the points closed and on when open. Almost like the points are not grounded which one side should eb and the other be insulated from the ground
 
I think your right about that screw not being insulated....i looked up some pictures and it showed a big platic insulator. Mine is just thin like cardboard material and is old looking. Thinking that under where i cant see the brass strip or washer is touching the arm that holds that screw, which would let the power flow to the dizzy body.

I will test the ohms tomorrow. So if i touch one side of multi meter to the dizzy body and the other to that screw that the coil touches what should it read?
 
Soundguy is talking on this too and right now we were thinking that it might be the insulator under the screw that the coil touches....the dizzy body is getting current through it
 
Ok Sound I just did that and touched one side to that screw and other to distributor body and read almost zero resistance. Is that telling us that the insulator is not good and allowing electricity to flow from that screw to the dizzy body?

Your saying it should be infinite if that insulator is good correct?
 
Great news....i cant see anything else it could be besides the insulator. I really hope this is it, the old cardboard insulator does look pretty broken down so somewhere i think the top or bottom washer or copper strip are touching where they should not. Its hard to tell by looking.

I think im just going to order a new distributor plate complete as the insulator is not replaceable and its pretty cheap.
 
Pop the plate out and recheck screw to plate just to make sure.

Its uncommon, but not the first one I've seen.
 
After I pop it out how would I hook it up to test it again?

I wish I could show a pic of the insulator, its not like the thick plastic ones I looked up today. Its maybe a sixteenth of an inch of ratty paper
 
As in how would i run power to the distributor plate itself to test it? If i have the plate out of the body can i just touch the coil spring to that screw?
 
I took the plate out and with my multi meter on ohms I touched one side to the screw where the coil would touch and one side to the plate....it read 0.01. When i did screw to copper strip or points it read the exact same 0.01.

My rookie thought is this is saying that screw is touching the arm to the dizzy plate and letting electric flow to the plate where it shouldn't?

Does this confirm the insulator aint doing its job?

I managed to get a pic on here but its upside down lol
 
Ok here ya go, this was the reading I got when touching screw to body. Same reading from screw to points and copper strip as well...
a234225.jpg
 
I just did the same thing with the points propped open and I get NO reading from that screw to the dizzy plate. So does that mean its not leaking power there? I chipped away at the insulator and it seems like the washer is directly touching the arm...
 
What does that tell you then? If theres no reading from screw to dizzy body does that mean the insulator is doing its job? Does no reading mean infinite?
 
No reading is infinite. Means insulator is good.

Now you have to find out why it tests good out, but tested bad in.
 
I didnt remember to open the points when checking it while still in the body....just did that now with points open and get the same infinite reading. So its not the insulator unfortunately it seems....

Im honestly lost and over my head soundguy
 
With the points open do you have battery volts on the condenser wire that is hooked to the points?? If you do not then the problem is in that area and you have a bad wire or copper strip etc
 
If you were local it would just be a truck ride :)

Here's the deal, power from battery, thru key, to coil top post, thru coil, out pigtail, to screw, to moving side of points.

All those should be battery volts when points open.

When points close its a complete circuit, voltage drop across resistor, and a lower than bat volts reading at the top of coil


You were reading less than bat at top of coil, meaning somewhere downstream from that is touching ground when points are open, effectively making them closed.

Is the pigtail leaning over and touching metal?

Is the screw shorted to the plate when under pressure of the pigtail spring?

Is the moving arm of the points shorting ?

Is the condenser wire or terminal end touching past insulator, or shorted itself.

Points close. Makes a circuit, coil charges, points open, spark happens.

Since your coo never sees open points due to a short from the pigtail to the points somewhere, you never get spark.
 
Long shot, but since so far, a problem still exists, check the points cotter key.....in your picture the upper bent leg looks awfully close to the metal spring/strip of the moveable part of points. When points open, can that touch?
 
I will check this first thing in the morning Old. Thanks for sticking with me Im not giving up on this thing
 
I would buy ya beer and food if you were close lol!

But I sincerely appreciate you sticking with me, Im not giving up on this. I didnt even know how to use a multi meter when I started this.

That is an extremely detailed list and first thing morning im going to run down it and report back with my findings!

Again thanks so much Soundguy
 
In editing my post on the phone I either deleted or left a piece out.

Key, thru resistor to coil

The resistor is on a 3 post wafer board.

2 top connections, one bottom.

Power from the bat via ammeter is at the bottom.

Key goes from bottom to one of the top posts. Resistor is across 2 top posts. Other top post is what goes to coil.

Thus battery to key, to resistor, to coil.

( to screw, to points ). With condenser connected to screw with short wire, and case hooked to plate just lil fixed side of points.
 
thanks for jumping in!

You are speaking of the long copper strip
touching the silver one that runs above it?
If so I believe they touch...i thought that
was ok because they come together anyway at
the screw?

And also something interesting....

Yesterday i decided to put the distributor
back together fully and attach the coil wire
to the coil....and for the first time I was
able to get strong spark with my test light
out of the cap in cylinder 1 and 2. Turned
the distributor over and test cylinder 3 and
4, not a single spark. I thought ok at least
I have half but when I turned it back to re
test 1 and 2 i got nothing. I fiddled with
some stuff and could not get it to spark
again.
 
(quoted from post at 15:32:21 08/12/16) thanks for jumping in!

You are speaking of the long copper strip
touching the silver one that runs above it?
If so I believe they touch...i thought that
was ok because they come together anyway at
the screw?

And also something interesting....

Yesterday i decided to put the distributor
back together fully and attach the coil wire
to the coil....and for the first time I was
able to get strong spark with my test light
out of the cap in cylinder 1 and 2. Turned
the distributor over and test cylinder 3 and
4, not a single spark. I thought ok at least
I have half but when I turned it back to re
test 1 and 2 i got nothing. I fiddled with
some stuff and could not get it to spark
again.
otter key to strap (circled).
 
Well didn't get to work much on it but had something interesting to share...

Yesterday i decided to put the distributor back together fully and attach the coil wire to the coil....and for the first time I was able to get strong spark with my test light out of the cap in cylinder 1 and 2. Turned the distributor over and test cylinder 3 and 4, not a single spark. I thought ok at least I have half but when I turned it back to re test 1 and 2 i got nothing. I fiddled with some stuff and could not get it to spark again.

Havea good weekend!
 
Ok i see what your talking about....man it
would be awesome if that was it and would
kinda make sense with that story i told you
about getting spark temporarily one
side.....the distributor is on the tractor
now so unfortunately it wilo be monday till
I get to find out
 
She lives again Soundguy! Turns out the snap ring that holds the distributor plate was just barely out of place by maybe 2mms and it was enough to barely touch the coil spring! So the points were fried from the bad coil and then that happened.

I really appreciate your help it made this happen!
 

She lives again! Turns out the snap ring that holds the distributor plate was just barely out of place by maybe 2mms and it was enough to barely touch the coil spring! So the points were fried from the bad coil and then that happened.

I really appreciate your help it made this happen!
 
Turns out the snap ring that holds the
distributor plate was just barely out of
place by maybe 2mms and it was enough to
barely touch the coil spring! So the points
were fried from the bad coil and then that
happened.
 
Good to hear. Sometimes the small stuff is what end up kicking a person back sides
 
Is the key suppose to turn it off by itself on these tractors? I have to take key out then throttle down and pull choke
 
Haha your right. It purrs like a kitten. Only thing im wondering about is it doesn't turn off with the key only. I have to throttle down and choke it and it shuts right off. Neighbor said it been like that forever
 
Yes, key off.

Sounds like you have an alternator that is misswired.
Charge stud essentially thru ammeter to battery. #2 spade looped to charge stud.

#1 spade thru a 194 lamp to the switched side of the key.

Every time you choke it to shut it off , you are reducing the service life of the engine via accelerated wear, reduced lube oil viscosity, etc.. Gas in oil, washed down cyl walls.
 
Oh man bummer, someone is coming to look at it soon. Would love to fix it first.

Forgive me but what are the spades? And what is 194 lamp?
 
If a Delco 10 si alt it will have a plug with 2 male spade terminals.

194# is a common trailer marker lamp.
 
Is it a 12 volt conversion?? If it is I bet the alternator on it is not wired correctly. If you look at it the alternator will have a 2 wire plug. If you look close it will have a #1 and #2 on the alternator and the #1 wire needs a diode or light bulb or resister in line so the excite circuit does not back feed the ignition and keep it running when you shut the key off
 
Yes it is a 12 volt converted. Ok im gonna try and look/fix it tomorrow but I might get lucky and have someone buying it anyways.
 
Just to prove that what I say is correct you can fire it up and then turn it off and carefully pull that 2 wire plug out of the alternator. If that is where the problem is then it will shut down because the alternator can not back feed the ignition because by pulling that plug your basically shutting off the excite circuit of the alternator
 
I think your right old....i havent got to work on it yet but I talked to my neighbor who said that it turned off with the key until he put a new alternator on it. So it has to deal with that.
 
A simple ballast resister lie the VR-1 or VR-2 from O'Reilly's auto parts store in the #1 wire will fix that problem and still have the alternator doing it job
 

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