46 2N coil

My 46 2N front mount converted to 12volt,kept 6volt coil with 2nd ballast resistor runs fine but when coil gets hot it quits. I know the coil is going bad. My question is if I replace with a 12volt squarecan will I still have the same problem eventually or are the new 12volt squares more reliable? Thanks

Are you using the right terminolgy, when you state 2 ballast resistor? A 6 volt coil in a 12 volt conversion, requires a 12 volt stepdown resistor to 6 volts (acts and looks like a ballast resistor), but with more resistance than a standard ballast resistor and the 2 in series (out one, in next one), apply the needed hot running resistance to a 6 volt coil. Testing resistors, resistance with a digital tester (when cold) might determine this. Testing the "voltage to the top of the coil" (when running), with an analog (dial type)meter should be about 4.5 volts. (digital tester give eratic measurement, when running.)
I feel these 2 resistors (12 to 6 volt and ballast resistor), with a 6 volt coil are a better choice than a 12 volt coil, with a ballast resistor since more of the heat is disapated in the resistors, than the coil. The front mount coil also suffers from more heat from the radiator
If you have 2 "standard ballast resistors" you do not have enough total resistance for a 6 volt coil, which will cause overheating and failure at operating temperature.
My experience is that it is hard to find a good square front mount 12 volt coil, but if you do switch I would recommend the ballast resistor.
Personally I like the 6 volt "original FoMoCO" resistor as I feel it has a better insulator between the windings.
HTH
Charles Krammin SW MI

Tom........unfortunately, neither the original 6-volt nor the modern 12-volt squarecan coil are as reliable as we'd like them to be. BOTH need the "infamous ballast resistor". Your current 12V conversion is using the WRONG 12-to-6V converting resistor. Most tractor parts stores do NOT sell the correct value.

I recommend a 2.5-ohm, 50-watt 12-to-6V converting resistor made from Radio Shack (2ea 5-ohm resistors in parallel) for use with the original 6V squarecan coil. It should be intuitively obvious, you do NOT use a 12-to-6V converting resistor with a 12V coil as you will have weak sparkies.

BTW, it takes about 1-hr of operation for the internal insulative tar to melt and cause weak sparkies. .......Dell, yer self-appointed sparkie-meister who knows 8-ways to convert to 12V and they all work the first time

Hi neighbor from 20 miles away! I converted to 12 volts about 1990, replaced the 6v coil with 12v coil from Ford dealer, and used two resistors (the white ceramic and the tubular with wire wrapped around it). Lasted fine without complaint until converted to electronic ignition last year. It was working great for 22 years, and worked fine when I took it off, kept in a box with the old points in case the EI takes a vacation. It'd probably take 15 minutes to convert back (by-passed both resistors with new round 12v coil, but left them there for potential need).

I mistakenly said I liked the "FoMoCo" 6 volt resistor, when it should have read "FoMoCo original 6 volt coil"

Charles Krammin SW MI

(quoted from post at 10:13:32 01/24/13) I mistakenly said I liked the "FoMoCo" 6 volt resistor, when it should have read "FoMoCo original 6 volt coil"

Charles Krammin SW MI

Click to expand...

hen last time measured? That sounds awfully high to me.
"Testing the "voltage to the top of the coil" (when running), with an analog (dial type)meter should be about 4.5 volts. (digital tester give eratic measurement, when running.) "

Thanks everyone for the replies & tips. I have an old squarecan Daddy had packed back & I think I'll try to do a round coil conversion. I found the posts in the archives which looks fairly simple, just a little time & work.