No spark

Try disconnecting the dist. pickup. With the key in "run" and a test spark gap rigged to the coil tower, tap the exposed terminal of the engine bay side of the pickup connector to ground. One fat blue spark should happen each time

Measure coil V with key in "run." Coil + should be say, 6--10v (it varies) but not same as battery. NEG side of coil should be quite low, 1 or 2 volts. Quite high indicates coil is not conducting. Box must be grounded

Try jumpering 12V temporarily direct to coil +

Ballast resistor must be good. (Continuity)