Not getting spark

so you have the black/ylw wire going to the - side of coil, blue/ylw wire to 12v side of ballast resistor, original wire to coil +. do you have a voltmeter? you need to check primary and secondary resistance @ coil. put it on ohms and check primary resistance by touching probes to + and - terminals. secondary is checked by touching one probe to either + or - terminal and the other touching the metal inside the coil tower.