12v conversion issues

Don Grigorenko · Mar 10, 2012

New to this forum. I have a '47 8N w/the front mounted distributor and coil. I lost the ignition key and replaced the key/switch and thought I could clean up the wiring mess under the hatch as I did so. Well, it has not gone well, and I don't know if I have damaged anything or not. I did the wiring according to a diagram that looked simple enough but it won't start. Not sure if I am getting spark or not. Also I don't know if the previous owner (who converted it to 12v) put in a 12v coil or not. Is there some way to tell if I have a 6v or 12v coil, and also, if the coil is good or not?

souNdguy · Mar 10, 2012

unfortunately, you've given us almost -0- info to go on what you say that it simply won't start.

does it turn over?

does it kick or pop or cough any?

does it have spark?

getting fuel thru the carb at the bowl drain?

is it a automotive style key-to-start.. or the oem safety starter setup?

is the oem ballast dash resistor in use?

any other resistors?

square coils come in a couple styles.. anemic 6v , that needs oem ballast resistor to run on 6v, and anemic 12v that needs a resistor to run on 12v.. ballast resistor seems to work fine for both. if you have the anemic 6v coil and are on 12v, you need the oem ballast resistor PLUS more resistance till primary current is in the 3-4 amp range..

post back some particulars..

soundguy

Don Grigorenko · Mar 10, 2012

Some particular:
1. It does turn over.
2. It does not kick or pop.
3. Don't know about spark.
4. Fuel sys was running fine before this so don't think that is a problem.
5. I put in an oem key switch.
6. I also replaced the oem resistor/terminal block (3 terminals).
7. There is another ceramic cased resistor screwed into the sheet metal under the oem resistor/term block.

Hope this helps. Don

souNdguy · Mar 10, 2012

lets see.

#3 is a problem, since you must actually do some work here... like pull the plug wire and see if you have spark. Hard to do that via clarivoyance from here.

#4 Hmm.. I wouldn't assume that because something worked 1 day, it would work now. What happens in that critical time between an object functioning correctly, and not functioning correctly?

'something' that's what happens.

a spec of cruck could have stopepd up a orifice in the carb.. or a flaot needle could have gummed and stuck.

again.. can't asusme anything.. you will physically have to pick up a tool and do some checking and post back.

soundguy

Dell (WA) · Mar 10, 2012

Don..........BOTH the original 6V squarecan coil and the modern 12V squarecan coil use the same MANDATORY "infamous ballast resistor". NO ARGUE!!!!

To use the original 6V squarecan coil on 12V, you need a ceramic 12-to-6V converting resistor AND the "infamous ballast resistor" connected together in series like flashlite batterys. Just like a flashlite, it doesn't matter which resistor is first, you just need BOTH to run on yer 12V conversion.

Surprizingly enuff, the "infamous ballast resistor" is very rugged and seldom goes bad. And when it does go bad, it goes bad just like a lightbulb ...ie... it either works or it don't.

Caution: the ballast resistor glows RED and is HOT. (burnie-burnie) ........Dell, a 12V advocate for the right reason. I just haven't found the right reason to convert my eazy starting 6V 52-8N. And I know 8-ways to convert and they all work the first time.

Don Grigorenko · Mar 10, 2012

Thanks. I will determine the spark first. It looks like the coil is newer (clean) so it might be that the coil was replaced with a 12v unit included with many kits. Appreciate your patience; just getting into the 8N world. I am planning on pulling much of the tractor apart and cleaning it up and painting etc.

Bruce(VA) · Mar 10, 2012

There are a few ways to determine if it's a 6v coil or a 12v coil. Being clean isn't one of the ways.

While the other resistor might be for the lights, chances are it was for the coil. So you might have a 6v coil w/ the OEM ballast resistor (on top of the terminal block) and the additional resistor to limit coil current to 4 amps or less.

As the tractor isn't running, you can't measure the current. But you can measure the resistance.

A digital multi-meter has two probes & a switch. Set the switch on resistance. Put one probe on the top of the coil & the other on the pigtail at the bottom. It will give you a reading in ohms. If it reads 1.5 ohms or less, it's a 6v coil. If it reads 2.5 ohms or more, it's a 12v coil.

If it's a 12v coil, all you need is the OEM ballast resistor. If it's a 6v coil, you need the OEM ballast resistor & another resistor of a value to be determined by the internal resistance of the coil.

50 Tips

souNdguy · Mar 10, 2012

keep us posted

Anonymous-0 · Mar 13, 2012

Helpful. I will check it out with the meter. If it is 6v and bad I will replace it w/a 12v.

12v conversion issues

Don Grigorenko

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souNdguy

Well-known Member

Don Grigorenko

New User

souNdguy

Well-known Member

Dell (WA)

Well-known Member

Don Grigorenko

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Bruce(VA)

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souNdguy

Well-known Member

Anonymous-0

Well-known Member

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