Why do the ignition boxes fail?
Mount the hei on the firewall Inside the car.
Use unused cavities on the bulkhead connector to pass the wires back and forth.
As to why they fail...
Several reasons come to mind
- Too much draw by the coil for the electrical components inside the box
- Low quality components inside the box
- Poor quality power feeding the box, too much electrical noise / spikes etc
- Heat
- Vibration