Lebron No Start- No Spark!!!

HOW DO these simple tests work and what do they show?

The "tap test" using the distributor connector shows that the box can be triggered, but it does not absolutely prove that the box is OK. The trigger circuit could still have a problem. This tends to check most of the box, wiring, coil, and power from the key switch

Measuring coil voltage shows that the box is loading down the ballast and that it's getting power and conducting current through the coil. This means the box is grounded properly, the main transistor is properly conducting, and that the coil is not open

The cranking test shows the same thing with the changed circuit caused by the contacts in the key switch.

What you cannot thoroughly check is the distributor. Just because the pickup shows continuity does not mean it's good. The distributor connector is troublesome, as there is very little power through there--just the minute power generated by the pickup itself.

There us still a certain amount of "gamble." If all the checks are good and it still won't make spark, there can still be an oddball problem with the box, or distributor. But doing these checks narrows the "gamble percentage" and eliminates wiring and power issues.