Terminal block wiring on older 8n

Now if you have a 8N with a front mount dist/coil it is a special animal. Originally it had a resistor built into the terminal block because the coil is really about a 3 or 4 volt coil. As Bob said it supplies 6V on start up but as it heats up it reduces voltage to the proper amount. If you were to take this resistor/terminal block out and replace it with a 2 terminal one with out the resistor it would burn up the points and coil.

But I think you have 12V's so you are even more special. If you are using the original 3 or 4 volt coil you will need a 12V to 6V resistor AND the original resistor wired in line to knock it down from 6V to 3 or 4V's.
They also now make a 12V coil for the front mount dist. I do not know if this coil needs a special resistor or not. Some 12V coils work on about 8V's and I am not sure about this one.

So if your terminal block is corroded and you still have the original coil you need to replace the terminal block with the original one with 3 terminals.

Maybe Bob can comment more on this now or you can go over to the 8N board and talk to a guy named Dell. He knows these front mount N's inside out.

I missed his post below about 12 Volts.

The original front-mount 6 Volt coil, for use on 12 Volts, needs the original ballast resistor PLUS a 6 to 12 Volt CONVERTING RESISTOR. This is an automotive ballast resistor measuring about 1.6 Ohms.

If he is using an aftermarket "12 Volt" coil, he still needs to use Dell's "trick current limiting resistor ahead of the coil, but DO NOT use the original ballast resistor with this setup.

The "trick current limiting resistor" consists of 2 - 1 Ohm 10 Watt resistors connected in PARALLEL to make a .5 Watt, 20 Ohm resistor.

This "trick" resistor prolongs breaker point and coil life, and is needed because it seems the aftermarket coil manufacturers spec'd the coil out to work at about 13 Volts, rather than thee 14 to 14.75 Volts a 12 Volt alternator system actually operates at.

The third terminal is simply an insulated junction point.

The original resistor, or a CORRECT replacement is a POSITIVE TEMPERATURE COEFFICIENT resistor.

When the ignition is first turned on, the resistor has a low resistance, for better spark while starting (the load of the starter draw on the battery pulls the battery voltage down, weakening the spark).

Within a minute or two, the resistor heats up from current flowing through it, and it's resistance increases, dropping the voltage to the coil, for longer point and coil life.

A generic ballast resistor from an auto parts store MAY OR MAY NOT be temperature compensated.

The non-temperature compensated resistors are generally a higher resistance, and are used on systems that have a switch in the starter solenoid to apply full battery voltage to the coil while the starter is cranking, and are generally for 12 Volt systems. If you are still 6 Volt, the OEM resistor is your best bet.

If you can clean the connections on the old resistor, and the coiled resistance wire is not damaged or broken, MOST LIKELY, it'll work OK.

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