Electrical Problem 1971 Duster

My Duster will not start. It will turn over but not fire.
If I pull the coil wire off and turn the engine over it will arc when the key is turned on then no arc while the engine is turning. When the key is turned off it will arc. What causes this? It has the 2 wire distributer Thanks!

Check the ballast resistor connections for 12 volts with a volt ohm meter on the coil side of the resistor with the key in the start position now
Another issue can be caused by bad grounds on the electronic ignition box also

Buklkhead is another spot where the wires have a bad connection.

Check the brown and blue wires for power in start and run.

if you put the key to on and then jump the starter relay, see if it runs.

if it runs, then either the ignition switch, bulkhead connector or the connector at the bottom of the column(assuming column switch ignition)
could be bad and not letting power go in the start position.

the balast resistor is bypassed during start.

Hold the coil wire (dist end) 1/4 from ground. key on. seperate the dist pickup zigzag 2 wire connector & drag the male tip of the body half of the connector across the intake to make/break ground & see if the coil wire sparks. Pull the yellow wire off of the "ign" terminal on the starter relay & have someone hold the ign key to "start" & redrag the connector & see if the coil wire sparks. check the reluctor gap in the dist (.008" with a brass feeler gauge) but "very close" is good enough for now. is this a 5 pin ECU/4 terminal "dual" ballast system or a 4 pin ECU/2 terminal "single" ECU system? Can you ohm your ballast for continuity?