1947 with the original motor. It is converted to 12v negative ground. I have a Mallory ignition coil with a ballast resistor mounted on the firewall in line to it. I have a problem where when I'm driving it looses spark. It just shuts off and won't restart. I check with a test light and I have power going into the ballast resistor but nothing/not much coming out. I replaced the ballast resistor with a new one and I replaced the Mallory coil with a NOS Mallory coil and I still had the same problem. The second time I bypassed the resistor by hooking the two wires together and replaced the Mallory coil with an old Ford yellow top coil. At the time I thought it was internally resisted but now I don't think it was, but it got me home. By the time I get home I hooked up the Mallory coil and ballast and the car started right up again. Anything else I should be looking at?
For what it's worth, I am using a #29150 Mallory "electronic ignition coil" with a Mallory #700 ballast resistor. I'm wondering if its not the right coil for running with points. Though before I put this NOS one on, I had another 29150 with another one of the same type resistors on the car for about 5 years with no problem. Now they have both been replaced and I still have the same problem, a problem that goes away when I bypass them... How do I measure the primary resistance of the coil? I've been reading that it needs to be 3 ohms when combined with the ballast resistor, which I know how to measure. If anything I would think that the coil being for electronic ignition would be less ohms, would that make it more prone to heat failure? Perhaps I'm being naive expecting a nos 40 year old coil to be reliable?
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