Ballast resistor

[MN_2N]

Hi All,

I have a 2N 6V and my coil went bad. Before putting in a new coil I tested the resistance on the ballast resistor and it shows no resistance (I get the same reading as when I touch the two leads to zero it in). My ohm meter is an analog meter and capable of measuring on the 1/10th ohm scale.

Do the ballast resistors sometimes loose all resistance when they go bad?

 

[Bob]

It is FAR more likely that your meter is not accurate at low resistances than that the resistance has gone away from your ballast resistor.

 

[Bruce (VA)]

" I have a 2N 6V and my coil went bad"

How did you determine that?

" I tested the resistance on the ballast resistor and it shows no resistance "

As Bob said, the problem is most likely your meter.

The specs on the OEM ballast resistor are .03 ohms cold & 1.7 ohms hot.
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[JMOR]

(quoted from post at 01:16:00 05/23/14) It is FAR more likely that your meter is not accurate at low resistances than that the resistance has gone away from your ballast resistor.

ob is correct. 0.4 Ohm (cold) is difficult to read on a standard meter. Use an ammeter & a voltmeter to set, say 4 amperes through the resistor & measure the voltage across the resistor. R= volts/amps.
For example, R = 1.6v/4A =0.4 Ohms. You have to be quick, as it heats up, the resistance goes up.

 

[MN_2N]

(quoted from post at 13:24:56 05/23/14) " I have a 2N 6V and my coil went bad"

How did you determine that?

...

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Well, the other day the tractor wouldn't start. I determined there was no spark. After checking the plug wires, I pulled off the coil. I checked for resistance between the primary and secondary and it showed infinite resistance like an open circuit.

 

[Bruce (VA)]

Left the key on?

 

[MN_2N]

(quoted from post at 00:21:36 05/24/14) Left the key on?

I don't think so but I'm not sure. The points are still good.

 

[Bruce (VA)]

" I don't think so but I'm not sure."

At $30 a pop for a coil, I think I'd check my ignition switch.

While they usually fail open, they could fail closed.
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