Ford 9n no spark - anyone help diagnose?

Anonymous-0

Well-known Member
I know this question has been asked a million times :) But looking for some guidance.

Have a 9N, front mount, 12v.

Used it all day yesterday drilling some post holes and when I went out to start it this morning, no start. Hmm, I put brand new plugs in it, no start.

Test for spark, no spark.

No voltage at ignition coil, suspect ballast resistor, take that off, sure enough it's physically broke. Cool. I figure, to verify, I can jump the 2 wires going into the ballast resistor and check for spark... if spark, I should be good in assuming that, ya?

Well, I jumped the two real quick, and cranked, no spark.

I do get voltage at the coil with them jumped and key on and on the ballast resistor...or the jumped wires anyway.

Before I start replacing things... I just wanted to find out if there's anything else I should be checking? Seems a little strange the tractor has ran so well and then all of a sudden BOOM. Nothing, after running great all day.

I did also notice on the coil, there is a hairline crack going down the side...if that helps anything (6V coil still I believe...)

Thanks ya'll!
 
Put a test light on the lead to the top of the coil. Turn the ignition on and attempt to start. Light should blink on and off. Report back.
 
No test light, just a voltmeter.

With the ballast resistor connections jumped, and meter hooked up to coil, it just drops from 12ish Volta to 11.3 when cranking.
 
if your ammeter has 10a unfused setting. put inline with coil and bump over and see if you can get it to go from 0 current to 2-4 amps... ( points closed )
 
" suspect ballast resistor,"

The picture is the OEM ballast resistor. Is this what your broken resistor looks like?

Any other resistors in the circuit?

" 6V coil still I believe.."
"I did also notice on the coil, there is a hairline crack going down the side "

Well, if it's a 6v coil w/o any other resistors.....and it has a crack in the coil......and no spark.....I think you might have found the problem.
IMG_20130902_090805_821_zps36da926e.jpg

75 Tips
 
Thanks for your reply.

It's the ceramic one, like this one attached. Inline to the coil.

Measuring across the coil terminal to spring, I was seeing about 1.3 if that helps. Again, seeing this thing with a crack...I think the answer may be right in front of me.

http://www.link_disallowed/photos/forum_3011.jpg
 
I think I just fried my meter trying this. Wasn't sure what to hook ground up to.

Had the 10A unfused setting, and set to DCA ... top of coil and ground and smoke started coming from the non-unfused port.

Saw around 2 or so constant while cranking.
 
Well, I'll assume that piece of paper that came with your meter was thrown away and completely ignored.. The one with instructions on how to properly use your meter!

voltage measurements are mades across locations in a circutt, like across a load, IE in a parallel fashion. Ammeter is used in series with a circuit, IE wire from key to meter, from meter to coil, the way you hooked it up provided a 'shunt' to ground.. With your meter ckt board being the short lived shunt becoming a short!!
 
I'm comfortable with most things, voltage wise.

The later, not so much :) I'll chalk that up to a nice $15 lesson.

Now that I think about it, it makes total sense. I'm an idiot.

Thanks though.
 
" I'm an idiot."

Nope.

You just learned a valuable lesson for $15.

:)

Sorta like my learning experience on setting the timing on my 29 Ford.

Car runs much, much better w/ the rotor in the distributor & not on the running board.
IMG_20130811_101227_149_zps31c8c27a.jpg
 
Agreed, sometimes the best lessons are the ones that cost. And the 15$ meter, was good tuition with not much real long term loss
 
ARE YOU TALKING ABOUT THE WIRE COMING FROM THE IGN SWITCH? ON A FRONT MOUNTED DIZZY WITH A STOCK COIL WONT THAT WIRE ALWAYS BE HOT(ENERGIZED)?
 

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