12v conversion wiring questions.

[Gantt]

I have a 46 front mount distributor and I am swapping over to a 12v conversion. I bought the kit here at YT. I am very confused, the instructions say to use the original ballast mounted on the dashboard. My tractor did not have this installed when I bought it, it had the rectangular shaped two terminal resistor instead.
My kit came with a new resistor, but says it should be installed inline between the existing resistor and the coil. It shows the original resistor as being a three post/terminal. Instructions say to use the new resistor if needed, but does not offer a way to see if it is needed or not.
I will post a picture of the resistor where it was originally mounted.

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[Royse]

YT also sells the original style resistor - [b:2bd775bb6d]Here[/b:2bd775bb6d]
The wire wound resistor is variable. Almost no resistance when
cold to give you better spark for cold starts, then the resistance
goes up as it warms up to keep from burning up the ignition.

The ceramic block resistors are a fixed resistance.

The way to know if you need the added resistor is to add up the
total resistance in the circuit, coil and all resistors, with the end
goal being a running current of right at 4 amps.

What I normally do is use the original resistor and a 12V coil.
That's about as simple as I can get the job done in my opinion.

 

[Gantt]

It was running for years before I bought it just as it was before I tore it down. The previous owner would occasionally charge the battery since he was running a 12v battery on a 6v system.
Should I buy the three post resistor?

 

[R Geiger]

If it were my tractor I would buy the original ballast resister and a 12 volt coil and be done with it. You may have gotten away with it the way it was because using a 12 volt battery on 6 volt system you were never really running it on a full 12 volts, or not at what you will be when the alternator is charging at around 14 volts. JMHO

 

[Bruce (VA)]

I can not understand why vendors will sell a 12v front coil AND a fixed resistor then tell you to use the oem ballast resistor as well.

IF it truly is a 12v coil, it will have right at 2.5 ohms of internal resistance. The oem ballast resistor is 1.7 ohms hot. At 14.5v running, that gets you 3.45 amps. That's fine. And, at .3 ohms cold, you get a nice spark at start up w/ about 5 amps.

The basic problem is that the fixed ceramic resistors are all over the scale in value. Some are 1.5 ohms, many are greater. Too much resistance and it won't start. Too little and you let the smoke out of the coil.

Check out tip # 39.

And do as Royse suggested.
75 Tips

 

[tractorguy2]

I sell A&I Products. They require using the ceramic resister
with there new 12v coils. That tells me they are not selling a
true 12v coil.

I'm guessing that's why your kit supplied a resister with the
new coil. If you use the new coil you will need both the oem
resister mounted on the dash and the new resister.

No matter what coil you use. You will always need the oem
resister on the dash.

My 9n is converted to 12v. I have the original Ford 6v coil with
a ceramic resister and the oem resister. I made a bracket and
mounted the ceramic resister above the starter switch where the
generator cutout was mounted. It is out of the way and looks
like it belongs there.

 

[Gantt]

I have 2.3ohms through the coil. So I ordered the original resistor and will not need the inline resistor.
Thanks for the help, this place is invaluable

 

[Royse]

"It was running for years before I bought it just as it was before I tore it down."

I bought one that was set up that way too and it ran fine for years.
It had enough resistance not to burn the coil or points.
Mine was always harder to start when cold than it needed to be though.
Mine was 6V and the engine rolled fine, but it had trouble firing and running.
Running a 12V battery on a 6V ignition may have masked that problem.

 

[Gantt]

The new ceramic resistor is filled in so I cannot see the Inside. The old ceramic resistor has a spring piece inside it.
The square style is variable or fixed?
Or is the rectangular ceramic style variable?
I am confused.

 

[HFJ]

ceramic resistors are, as far as i'm aware, always fixed. it doesn't matter if u can see the inside or not.

 

[Tim PloughNman Daley]

Something ain't wired correctly on your setup the way it is. What is the ceramic resistor fastened to - the switch, cutout, or the ammeter? Your 2N has the front mount distributor. It also has the square can coil and the OEM Ballast Resistor. They also use a 1-Wire/3-Brush 11 AMP generator with a roundcan cutout circuit (behind dash), and a 1-wire starter motor with NO solenoid. Is there a problem with your 6V/POS GRN system? It's your tractor and you can whatever you wish, and there is nothing wrong with a 12V/NEG GRN setup, but many newbies (and a few oldies who don't know) think a non-starting issue is due to a 6V system. Basically, they just don't understand and don't have the time to think it thru logically. There can be many reasons why it won't start, regardless if 6V or 12V and 99.98% of them are due to incorrect wiring. If it doesn't run on 6V now, what makes you think it will on a 12V switch over job? If you don't already have them get the Essential Manuals. ALL 9N/2N, and early 8Ns use the front mount distributor, square coil, and the Ballast Resistor. When one changes out from a 6V POS/GRN setup to a 12V/NEG GRN system, you still use the Ballast Resistor, and coil but need to add the white ceramic 1-OHM resistor in the circuit ONLY IF you are using the OEM 6V coil. You can get a 12V coil and not connect the in-line resistor at all - as many have recommended. On a 9N/2N you need a 12V battery, new 12V battery cables, new 1 or 3 wire alternator with tension bracket, new belt, and remove the generator,cutout, 6V battery, and cables. You will also need to consider a new wiring harness at this time.

FORD TRACTOR 9N & 2N OEM 6V/POS GRN WIRING:

<img src="https://i.imgur.com/QWaC1aah.jpg">​

<img src="https://i.imgur.com/CJedLEch.jpg">​

FORD 9N & 2N WIRING 6V & 12V:

FORD N-SERIES TRACTOR FRONT MOUNT DISTRIBUTOR 9N-12250 BALLAST RESISTOR:

EXTERNAL IN-LINE 1-OHM CERAMIC RESISTOR ? REQUIRED WITH THE FRONT MOUNT DISTRIBUTOR WHEN USING A 6-VOLT COIL:

FORD 9N-10505-B CUTOUT ?USED AFTER S/N 12,500 TO S/N 258504 ON 9N & 2N MODELS ONLY:

*NOTE: When doing a 12V switch over job, the cutout is eliminated along with the generator.


FORD 9N/2N TRACTOR ESSENTIAL OWNER/OPERATOR/PARTS/SERVICE MANUALS:

Tim Daley(MI)

 

[Gantt]

it was not hard to start, rather a new 12v battery was already installed, so i cost me 105 bucks to swap to 12v vs 7-90 bucks for a 6v battery. i preferred to spend a little more and just swap to 12v.

my main confusion was the resistor block that was missing. tractor runs now with the ceramic block installed, but i have the correct part ordered and on the way.

 

[Hobo,NC]

(quoted from post at 23:37:28 02/15/20)
I have 2.3ohms through the coil. So I ordered the original resistor and will not need the inline resistor.
Thanks for the help, this place is invaluable

Wire it up on your work table use your DVOM on the 10A setting wired in series to determine the amp draw of the coil do not leave it wire up for more than 30 seconds are you may fry the coil. Use ohms law to verify your findings if for nuttin else you will get a quick education on how ohms law works and what the others are trying to explain to ya.

I don't mean to muddy the water your supplied fixed rectangle resistor is not fixed it can't be nor any other as far as that goes as it heats up amps go down tho it may be minimum.

(Heat) ohms go up amps go down
Ohms go down amps go up.

One more thing to remember Ohms can tell you if its bad but cannot tell you its good : ( Ohm checks are to be used with the part is in a static state and never in a dynamic state and that's were your amp function on your meter comes in handy you can test it live. The true goal of all of this is to control the amps so your coil will live a long health life...

Guess whut this will apply to your day job not just yer tractor... : )

 

[Gantt]

i will give this a go this weekend

since the tractor is not going to be ready for spring due to engine knocking, i may push it to the side and work on my motorcycle. got a set of custom ground cams and a thin head gasket to liven it up some. warm weather is around the corner and i need a project to boost my motivation and self esteem again. haha.