> I have a Mallory dual point distributor with an Allison
> 40K coil, along with an in-line resistor of 1.6 ohms. Point gap on both
> sets of points set to 0.022 inch. When I disconnect the coil, an ohmmeter
> connected between the primary input to the distributor and ground
> shows that
> the points resistance is going from about 3 to 6 ohms to infinite as I
> rotate the distributor.
> A resistance check on the coil shows about 0.3 ohms through the
> primary and about 8.5k through the secondary.
3-6 ohms is too high for closed points, especially with the very low primary
resistance coil you are apparently using.
> Has anybody seen this problem before? What am I missing? My
> only guess is
> that the resistance across the points is still high enough when
> closed that
> current is still flowing through the test light.
Exactly.
Assuming for the sake of argument that the supply is 12v, and the closed
points are 3 ohms, we can work out the voltage across each component :
Total resistance 3 + 1.6 + 0.3 = 4.9 ohms.
Voltage across points = 3 / 4.9 * 12 = 7.3 volts
voltage across ballast = 1.6 / 4.9 * 12 = 3.9 volts
voltage across coil = 0.3 / 4.9 * 12 = 0.7 volts
As you can see, this is way out of whack.
That ballast also seems high for that coil, you might double check that you
have an appropriate match. In fact, the coil seems very low to me, period.
I wonder if it's internally shorted ?
Randall
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