The white trigger wire is to be used for points and is typically not used in a simple electronic pick up system. Disconnect the green/purple plug. With the ignition hooked up to the coil, battery and ignition wires hooked up and on, put a spark tester or grounded spark plug in the coil wire, make and break the white wire to ground. Each time you break the white to ground connection should produce a spark. This verifies the box and coil condition. Spark? Pick up. No spark? Try the coil. Still no spark? Box.