In Reply to: resistor question posted by Tim Lalonde on May 12, 2020 at 19:20:26:
Not sure what you are calling the 'first resistor', but we have a ton of self-help info in our HOW-TO's FORUM -see LINK. Don't assume because your battery is 12V you have your system wired all correctly for the changeover. If you mean the OEM Ballast Resistor crossed and shorted out, how do you know? How did you test either one? Like Bruce said, on the OEM Front Mount distributor, whether 6V/POS GRN or a 12V NEG GRN switch over job, you need the OEM Ballast Resistor wired in line. If you have a 6V coil and go to a 12V setup, you need to add an external 1-OHM ceramic resistor wired in line. Just to be sure, with a 12V job, you remove the OEM generator and the OEM Voltage Regulator on an 8N and gen & cutout on a 9N or 2N -you don't say which model. The LH terminal post on the Ballast Resistor only connects to the coil single terminal post on the distributor. Take your VOM, set to VDC, and place one probe, doesn't matter which, on the resistor post and the other probe to metal ground, turn key ON but don't turn over engine. Reading should be battery voltage with points open, half that with points closed. 99% of all non-starting issues are due to incorrect wiring regardless if 6V or 12.
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: