spark question, can't remember fix

Yup, probably
The fact that you get the one spark, going to key-off proves that the ECU is alive, and obviously the coil is good and so is the wiring on the run side of the dual ballast resistor. So that just leaves two possibilities 1) the crank side of the wiring or 2) The crank side of the dual ballast resistor. Experience says resistor.And the runs til hot kinda proves it.I say kinda, because it could be a high-resistance connection at the resistor. I say could; but not likely.