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Alternator shorted, now 'no sparky'

W

WeekendWarrior

New User
I use my 9N for just about everything, including weekly mowing. Recently I was mowing the lawn and the motor unexpectedly died. I discovered that the wire from the alternator to the battery melted on the exhaust manifold and then managed to weld itself to #4 spark plug!

Now my 9n will not start, I have no 'sparky' at any cylinder. Here is some important info about my setup and my testing so far:
9n
Front mount distributor
12v negative ground with GM alternator
Ballast resistor
Round automotive style coil

I installed a Pertronix Ignitor electronic ignition kit in February and it has been running like a champ until now.

Tractor came without the original wiring harness, and they weren't using a ballast resistor, so I burnt through a few square can coils and messed with TSC melted points before installing the EI. It has been running like a champ for months and starts in -20 or 90 degree weather all the same.

Here's what I have tested:
I have 12+ volts at the battery, after the ignition switch, after the ballast resistor, and at the coil.
Disconnecting the alternator has no effect on the starting problem.
I took the automotive coil out and used it to start up an old van, which ran fine on the coil (coil works).
I took the distributor out and bench tested it according to the manufacturers instructions and it WORKS! When I rotate the dist shaft the voltmeter shows 12 to 0 and back to 12v as I rotate it, which is the desired result.
Here's the kicker: when everything is reinstalled on the tractor and I crank the motor with the voltmeter on the neg side of coil and grounded to battery there is 12v and it does not alternate to 0. I don't know if this is to be expected (maybe it happens too fast to detect?).

In any event, my 9n will not start since the alternator wire incident. I'm scratching my head over here....any advice or suggestions are welcome. And yes, I know I will take flak for installing the EI!
 
(quoted from post at 23:05:25 06/28/17) I use my 9N for just about everything, including weekly mowing. Recently I was mowing the lawn and the motor unexpectedly died. I discovered that the wire from the alternator to the battery melted on the exhaust manifold and then managed to weld itself to #4 spark plug!

Now my 9n will not start, I have no 'sparky' at any cylinder. Here is some important info about my setup and my testing so far:
9n
Front mount distributor
12v negative ground with GM alternator
Ballast resistor
Round automotive style coil

I installed a Pertronix Ignitor electronic ignition kit in February and it has been running like a champ until now.

Tractor came without the original wiring harness, and they weren't using a ballast resistor, so I burnt through a few square can coils and messed with TSC melted points before installing the EI. It has been running like a champ for months and starts in -20 or 90 degree weather all the same.

Here's what I have tested:
I have 12+ volts at the battery, after the ignition switch, after the ballast resistor, and at the coil.
Disconnecting the alternator has no effect on the starting problem.
I took the automotive coil out and used it to start up an old van, which ran fine on the coil (coil works).
I took the distributor out and bench tested it according to the manufacturers instructions and it WORKS! When I rotate the dist shaft the voltmeter shows 12 to 0 and back to 12v as I rotate it, which is the desired result.
Here's the kicker: when everything is reinstalled on the tractor and I crank the motor with the voltmeter on the neg side of coil and grounded to battery there is 12v and it does not alternate to 0. I don't know if this is to be expected (maybe it happens too fast to detect?).

In any event, my 9n will not start since the alternator wire incident. I'm scratching my head over here....any advice or suggestions are welcome. And yes, I know I will take flak for installing the EI!
Click to expand...
I took the distributor out and bench tested it according to the manufacturers instructions and it WORKS! " Really? What does that mean? What are those "manufacturer's instructions? The distributor manufacturer was Ford and Ford had no EI? Pertronix has an EI unit not a distributor. So I have no idea what you "tested" or how. So , not much to go on at this point.
 
WEW.........iff'n ya putta 12-volt round can coil in, why didja install the infamous ballast resistor??? Besides the ballast resistor was Fords electrical trick fer the weak sister squarecan coil. Final comment, iff'n yer volts don't alternate 0-12-0 etc, yer points (0.015) are NOT opening. Iff'n yer expecting the volts to alternate at idle, you'll read about 8-volts. Negative (-) ground or positive (+) ground, starter motor always turns the correct direction to start yer engine. 12-volts just makes it turn faster. Inna worn engine this kenn be a benefit. As fer EI, I stick built an EI in 1963 fer my 1956 Dodge D-500 with semi-hemi V8. Ran like snott. I just think Pertronix sucks in the weird 4-nipple frontmount. Works pretty good inna 5-nipple sidemount. Oh yeah, the 12-volt alternator ALWAYS demands negative (-) ground. NO ARGUE!!!........HTH, the amazed Dell and self-appointed sparkie-meister
 
Clearly you understood I was referring to
the EI unit, but you just had to troll, and
argue symmantics. Congrats, you win the
troll award.
Now, if you have any constructive comments
or questions I'd love to hear them. I've got
a broken down tractor, a couple acres of
tall grass, and some rows of potatoes that
need to be hilled.
 

If I understand how you are connected on the tractor, after the coil and before the distributor, the EI is not closing. I know you said it worked on the bench. On the tractor you should see 12 volts when the EI is open (not conducting) and something less when it is closed (conducting).
 
Yes, that's what I expected to be seeing,
but for some reason when it's installed on
the tractor and I have the voltmeter on the
wire coming from the EI module to the coil I
am only seeing 12v+. It does not alternate
down to 0 as I crank the motor. The voltage
dips slightly as the motor cranks but never
below 11v.

What I can't figure out is why it works
properly on the bench but not on the
tractor.
 
Thanks Dell, I was hoping to get a reply from the infamous "sparkie-meister". Thanks also for pointing out the ballast resistor issue.

I had installed the ballast when I first bought the 9n and it was missing (I melted a few square coils first). At that time I was still running points and a square can.

Although I have to mention that my current setup (round coil with ballast and EI) has been running flawlessly for over 4 months).
 
I was going to comment as well, but will also abstain.

Congrats, you've just driven away 3-4 of the probably 6 people on this board that actually understand or have had formal training in electronics.

Good luck!
 
My attitude is this: I am incredibly appreciative of this forum, it's wealth of information, and the many contributors that have bailed me out of a bind.

That being said, I have never benefited from comments which do nothing to further the troubleshooting/diagnosis/repair conversation. The question posed had already been answered. I tested the distributor and I tested it using a voltmeter.
I also explained it was EI. I did not appreciate being put on the defensive over such a trivial error, and I would not have bothered to post otherwise.

Thank you both for your replying to say you will not be replying. Thanks for your time.

Hopefully someone can steer me in the right direction to try and resolve this. If not, no worries, and I will post an update if I come to any solution independently.

Thanks again
 
Pertronix Ignitor test procedure:

1. Connect a jumper wire from the Ignitor plate to the battery negative terminal.
2. Connect the Ignitor Red wire to the battery positive terminal.
3. Attach the red voltmeter lead the positive terminal of the battery.
4. Attach voltmeter black lead to the Ignitor black wire.
5. The voltmeter should read battery voltage once all the connections are made.
6. (Omitted. Applies to 1-3 cylinder motors)
7. Rotate the magnet sleeve in front of the module, as one magnet passes the module, the
voltage will drop to 0-volts, when the next magnet passes, the voltage will go up to battery
voltage.
8. If the voltage doesn’t drop and you read a constant battery voltage on your meter, the​
Ignitor has failed.

Again, this works when distributor is bench tested, but when installed it acts as though the Ignitor module has failed. I have replaced all wiring for the ignition setup (to and from dist, coil, ign switch, etc.), but still, no dice. My last resort is to throw a new Ignitor module at the problem.
 
My attitude is this: JMOR had a legitimate question based upon your not so trivial error of saying you removed the distributor and the EI and tested " it " on the bench. It's hardly a trivial grammatical error when you simply failed to communicate what exactly you were testing.

.
 
Ah, the "A" Team strikes again... If there is any 'sandpapering' to be done, they do it to you, not the other way around. So, on your Knees, Weekendwarrior...... :)
 
(quoted from post at 06:09:08 06/29/17) Yes, that's what I expected to be seeing,
but for some reason when it's installed on
the tractor and I have the voltmeter on the
wire coming from the EI module to the coil I
am only seeing 12v+. It does not alternate
down to 0 as I crank the motor. The voltage
dips slightly as the motor cranks but never
below 11v.

What I can't figure out is why it works
properly on the bench but not on the
tractor.
Click to expand...

- Might make sure the distributor is rotating when the starter is cranking the engine.

- I suspect you have different connections on the tractor than you did for your bench test.

- Note, I have a Pertronix module for my 8N for use with a, 6 volt, [u:a06ef04d87]positive[/u:a06ef04d87] ground system. I plan to install it when the present set of points give trouble. The wiring diagram for my system shows the positive side of the coil grounded and module is connected to the negative coil terminal. Since you have a [u:a06ef04d87]negative[/u:a06ef04d87] ground system the module should be connected to the positive coil terminal. The reversed coil connections should not prevent the system from working....but I would suggest double checking your connections.
 
That is a good point about the distributor
rotating and I can confirm that it is. I
also had a spare rotor laying around so I
swapped it to see if there was any change.
There was not.

Also an interesting point about the coil
wiring. My setup has been 12v+ from the
ignition switch (previously through ballast
resistor) to the positive side of the coil,
and the Ignitor module to the negative side
of coil.I can certainly test the opposite
connection, but it has been working in this
configuration daily for months. I'll give it
a try anyway and report back. Thanks for the
continued feedback
 
Although I suppose it will be an exercise in futility, I will entertain and respond to the absurd position you are forwarding.

In the sentence immediately following the one in question, I explain that I used a voltmeter to measure the output, and observed the 12-0-12 pattern. If your argument is that my statement on removing the distributor and bench testing it was ambiguous, I have the following question for you:

2.What other function of the distributor could I have been testing using a voltmeter, in a distributor with an EI?

The fact of the matter is that the ignition module cannot be bench tested if removed from the distributor, as the test relies upon rotating the cam while the module is installed on the breaker plate. So, I did remove the distributor, and I did bench test the distributor. I bench tested "it" according to the manufacturer of the ignition module.
 

Your bench test procedure is not using a coil in the circuit? Add the coil, positive terminal connected to black ignitor wire running to the volt meter. The negative terminal of the coil is grounded.

Repeat the bench test with the coil load.
 
"The fact of the matter is that the ignition module cannot be bench tested if removed from the distributor"

Weeky, I'm glad you cleared that up for us!

On the other hand, I HAVE more than once "bench tested" a pertronix module sans distributor by simply connecting it to a power source and a coil with test leads, then waving a hand-held magnet past the Hall-effect sensor in the area that faces the magnet ring when installed in a distributor. (And, yes, I had a spark tester connected between the coil's high-tension tower and ground.)

You should give it a try, it's FUN! Gotta think "outside the box" once in a while!
 
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