6v or 12v coil?

[Dave/MO]

I own a 41 9N that has been converted to 12v. What is the difference in amps between a 6v coil and a 12v coil. I am not sure what I have and the only resistor on the tractor is the ballast resistor. Do I need the resistor block or can i run with just the ballst resistor? Any info would be nice.
 

[old]

I believe what your trying to find out if not how many amps but what the ohm value should be between to 6 and 12 volt coil. I can not help you with that but figured I would make sure of what you are asking so maybe some one else can help you better then I can
 

[Dave/MO]

You are absolutely right. I meant to ask what the Ohm differences are. Sorry peoples.
 

[Bruce (VA)]

A 12v frontcoil will have an internal resistance of 2.5 ohms or more. A 6v frontcoil will have an internal resistance of .3 to 1.5 ohms.

You always need the OEM ballast resistor on a frontmount; 6v or 12v coil doesn't matter. If you have a 6v frontcoil & a 12v conversion, you will need an additional resistor to limit coil current to less than 4 amps. You do not need any additional resistors w/ a 12v coil.

See tip # 30 at the link below.
75 Tips

 

[souNdguy]

ditto what bruce said.

I personally like a 2.5 ohm coil and oem resistor combo.

best of both worlds in a compromise setting. hotter startup sparks that drop primary current in a few minutes after start.
 

[Charles Krammin]

On my 45-2N I run a 12V, positive ground generator, wuth voltage regulator and a 6volt (1.5 ohm) coil, with 2 resistors (!2 to 6 volt, ballast resistor. I like this setup, as the front mount coil is subject to intense heat from the radiator and this keeps it cooler. Ialso get 12volt hotter spark at cold statup. The positive ground also directs the spark to the center electrode of the sparkplugs. Points have also faired well in this setup.
On my Ford 600 sidemount, I however run a true 12volt coil, with ballast resistor (don't really need it), with switched wires on coil for changing polarity, as I use a Neg ground polarity alternator, with internal regulator. This setup also has all the good characteristics, as above. The "Tin can sidemount can stand the heat better.

Charles KramminSW MI