JD 50 Electronic Ignition Coil Temp.

HobbySaw

New User
Just installed an electronic ignition conversion with Flame Thrower ignition coil on a friends 1956 50. Tractor runs great but the coil seems very hot to the touch. Do these epoxy filled coils normally run hotter than original point coils? Scared to put her to work until I find out what to expect. Other info- 12 Volt positive ground system (correct kit), new voltage regulator installed charges at 12v at idle up to 14.5 at full throttle. Same battery as before, still checks good. Thanks
 
Measure the coil current. Odds are it's closer to 8 amps than 4 which it should be.
What resistance between the coil primaries?
 
No experience with a flame thrower but all the coil's I've seen that were very hot had the wrong voltage & were fixing to go BOOM.
 
Or measure the primary dc resistance (may be easier) which should be adequate to privide the 4-5 amperes that you want for your transistor switch to conduct. Taking a nominal 12v and 4 amps you need at least 3 ohms of dc resistance between the power applied from the ignition switch and the coil terminal that goes to the electronic ignition module. If you don't have it, get a ballast resistor in the circuit that will get you there.

Did you get instructions for installation, like a note that says that an xyz ohm ballast resistor is required with this coil?

Some ign. modules warn you that if you over current the circuit, which you seem to be doing, you can kill the module due to overheating the switching transistor.
 
Now the rest of the story! So I learn this history today, the tractor hasn't been run much in 8 - 10 years. They never could keep it going for long, now I find out (with you fellows help) someone back "then" rewired the tractor - without the resistor! Now to replace it--- any suggestions? What would work that I can get from the auto parts store?
 
Does the starter switch have the terminal for bypass starting.
Don't let anybody tell you that there really is a resistor inside some coils.
Do you want a tractor with bypass starting?
 
Over the years I have needed resistors and purchased them from NAPA auto stores. Main thing is that it is made for the occasion with some being one value like 1.5 ohms or thereabouts, and others with taps where you could add resistance to get what you want. Then they are mounted on white ceramic bases to insulate them from their mounting since they get hot with 2 holes for mounting.

Mark
 
i run them on my 50..60..a and g..u need a 3.0 ohm coil with internal resistor you probaly got a 1.5 ohm and you will need to put a resistor on tractor or get right coil ive done this by mistake it cracked coil cause it got so hot
 
Sorry for the late reply, been busy elsewhere. Here"s what we have now. Ignition resistor from an auto parts place, no idea of the resistance but tractor runs great with about 7-8 volts on the coil once all warms up. The coil now runs cooler than the generator (about 130F). All seems good to go. Thanks for the help
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top