Checking for spark:
You have two power sources so it's important to understand
With the key in "run" the ignition gets power from the "run" circuit, known as IGN1 IN MOST cars this goes dead when moving the key to "start"
When cranking the engine WITH THE KEY and IGN1 "run" dead, the ignition gets power from a second contact in the switch, a brown wire that feeds out to the coil + side of the ballast.
The point is if you are "checking for spark" and you are jumpering the start relay to do so, you will get a WEAK spark, because this bypass circuit is not active.
You can "rig" a spark gap with the coil wire and a plug, but it's better to use a spark gap tester and a solid--not resistor plug wire. Again, while using the key to crank, you should get a nice snappy blue spark, minimum of 3/8" and typically as much as 1/2" long
