[JRandomFreeper]

Diodes are likely to be blown in the alternators. They are after all, PN junctions.

Remember generators and relay regulators?

Batteries should be fine.

I'll manage. I've been winding coils (frequency specific) since I was 10.

/johnny

[editor-surveyor]

This would be remarkably easy to prevent with a simple relay that switches fron ‘on’ to ‘off’ when energized, placed from the alternator output to frame ground.

This would automatically ‘ground’ both sides of the diode when the engine is not running.