Ballast resistor

[Travis Troxell]

just got a '48 Cub for my wife for her birthday. Cool thing is it was locked up when we got it home but is cranking fine now. When doing the normal house cleaning on it and getting it ready to run (sat for years) when I hooked up the battery and flipped the switch to "on" to send power to the coil the ballast resistor started smoking? Previous owner had converted it to 12 volt and assume he kept a 6 volt coil. Ideas??

 

[JMOR]

(quoted from post at 21:42:09 12/26/11) just got a '48 Cub for my wife for her birthday. Cool thing is it was locked up when we got it home but is cranking fine now. When doing the normal house cleaning on it and getting it ready to run (sat for years) when I hooked up the battery and flipped the switch to "on" to send power to the coil the ballast resistor started smoking? Previous owner had converted it to 12 volt and assume he kept a 6 volt coil. Ideas??

he resistors run hot....hot enough to scorch paper..........it was probably just ridding itself of 6 years of accumulated dust, rat sheet, etc.

 

[John T]

I agree with JMOR those ballast resistors can be dissipating something like around 24 watts and that produces heat which can cause smoke n smells n other nasty "stuff" thats accumulated over the years when its heated, so see if she settles in once its ran a while. NOTE if you turn her on and leave it a long time yet shes not running that can make it and the coil realllllllll hot thats NOT a good thing to do. You might wanna clean her off a bit before you try again and it helps cool them if the metal bracket is tightly attached to a relatively cooler hunk of iron with air circulation and NOT in a place where heat gathers n lingers.

John T

 

[LJD]

Not uncommon. Especially if you had the power on, engine NOT running, and the points in closed position.