NO SPARK condition cured 84 silverado 305-LE9 (vin H)

[Ishtim]

With help from a another Forum user, we determined that the ESC box caused fault in ignition system. Fix: all new electronic distributor components (even though all were within tolerance except low resistance on pick up coil) and jumper the green and black wires of the 4 prong ESC module plug (at the distributor). It seems that the failure in the "sparkbox" disallows one of the transistors in the IGN module not to complete the circuit required for high voltage generation and... NO SPARK .

This was very confusing seeing that all components tested out to be within tolerance and the module tested out fine.