It's so nice to be overwhelmed with information on the subject. Thanks gentlemen.
I always looked forward to crash investigation reports, as morbid as that sounds, as they often filled in the gaps in my systems knowledge. i.e. providing details not even found in Maintenance Manuals, Wiring Schematics or FCOMs .
Cheers
P.S. I'm assuming the -9 is the same as the -8