Resistor

[littlepint]

I have a 1948 front mount 8N that has been converted to 12volts. The alternator has a internal regulator. There is one of those white block resistors in the 12 volt system-why is it there. I
also have a resistor inline with the coil and I understand why it is there, but do not understand the other one. Could someone explain . Thanks

 

[Bruce(VA)]

Your alternator is in the charging circuit; the white ceramic resistor is in the ignition circuit.

It's there because a PO decided to keep the 6v coil. Or, because the PO indeed installed a 12v coil and the kit directions said to use the ceramic resistor, thereby sentencing to a life time of a weak spark because you have too much resistance in the circuit.

See tip # 30.

Front distributor, owm ballast resistor w/ a 12v coil will work fine.

Check the coil; 2.25 ohms on the primary, it's a 12v coil.
75 Tips

 

[littlepint]

Thanks Bruce. I understand.

 

[Tim PloughNman Daley]

Yes, the Ford Front Mount Distributor uses the OEM Ballast Resistor, p/n 8N-12250 in the original 6V/POS GRN electrical system AND is kept in the circuit when doing a 12V switch out job. IF, when doing a 12V switch job, you elect to keep your 6V coil, then you need to add the external, in-line, white ceramic 1-OHM resistor to the circuit. IF you replace the coil with a 12V coil then you do not add the external resistor as Brice stated. Me? I'd opt for the latter since I don't believe in added whistles and bells dangling around. Get a good 12V coil -NAPA has them -and be sure to test it and not just go by what is stenciled on the box.
FORD OEM BALLAST RESISTOR -USED ONLY WITH FRONT MOUNT DISTRIBUTOR:

HELP: The LH resistor Terminal Post connects to the COIL Stud Terminal Post as you face the back off dash. OEM Wiring is RED.

FORD 8N TRACTOR EARLY OEM DASH PANEL WIRING, RESTORED:

EXTERNAL 1-OHM CERAMIC RESISTOR - USED ON FRONT MOUNT ONLY AND
ONLY IF COIL IS 6V:

Tim Daley(MI)