It is a plated steel ball in a magnetic cup that bridges the ground side of a relay. It should be mounted in a clean dry place out of direct sunlight. The button re-seats the ball if it rolls out of the cup. That is why the orientation is important.
You could remove the screws and bump it with your hand to simulate an impact that should unseat the ball.
Some info on the ELT inertia switch testing:
https://ntrs.nasa.gov/archive/nasa/casi ... 010544.pdfMazda used an output from the VAF to keep the pump on, so if the engine died, the spring loaded vane returns to its stop, and the pump stops.
GM has used oil pressure so if the engine stops, the pump stops.
I expect newer vehicles will stop the pump based on no trigger input from the engine.
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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS
viewtopic.php?f=5&t=13225&p=134742Simple Spring select
viewtopic.php?f=5&t=11815LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12