I have spark when cranking, but not in the run position


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Sep 1, 2022
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My car is a 1966 polara with the poly 318.

I have spark when cranking, but not in the run position.

I continuity tested the switch and its good

So I made a "Y" shaped jumper and put the single end in the BAT connector put the second end in IGN 1 then the third in ST. This would make the car crank but not run,

If I take the second end and plug into IGN 2 then the car will crank and run.

I haven't had time to probe the rest of the loom from the plug under the dash to the engine bay.

but I intend to do so over the next couple days, in the mean time I'm wondering if anyone else has had this problem and if they have any tips for me.

Thank you.
Ballast resistor failure. Classic symptoms. Fires when cranked, shuts off when the key is released.

The ballast resistor is the white ceramic thing found on the driver side hood hinge bracket. Check to see that the wires are connected in case one has fallen off... if so, reconnect and see if the car runs. If they're connected, then put a multimeter on it to check the ballast resistor's continuity - if it reads 0, then replace it, and your car will run.

The explanation is that the ballast resistor creates the required voltage for the coil to create sparks and permit the engine to run properly, but is bypassed when the key is turned to engage the starter. Once the key is released, then the ballast circuit is engaged. If the ballast resistor is bad, then the car will fire when the key is turned to start, but will not be able to continue firing when the key is released into the run position.


The ballast resistor may look slightly different in your car, but it will perform the same function.

Here is a picture of a 1966 Dodge Polara - you can see the white ballast resistor on the triangular shaped hood hinge bracket on the driver side, at the rear of the inner fender.

the ballast resistor has probably gone bad then, as I already checked most of the wire connections before resorting to the stuff in my first post in hopes of an easy fix.

thank you.
Get a heavy duty one, especially if you are running electronic ignition.
Buy two ballast resistors. One for under the hood to fix this issue, a second one for the glove box.
poached the resistor out of my valiant and the car started right up. thank you everyone.