Inertia Activated Fuel Pump Cutoff Switch
This switch is designed to open the circuit to the fuel pump in the event of a hard impact above certain G levels for a certain period of time. It is put in-line with the ground side of the relay that controls power to the fuel pump(s). Modern cars are running higher and high fuel pressures so if there is a breach in the fuel line during an impact, fuel can spray over a very large area very quickly; when loads are exceeded the switch opens and automatically turns the fuel pump off. Again, the vehicle has see a high G impact over a very short period of time, forces way above hitting curbs or bottoming the car out or bumping other cars or high braking and lateral accelerations. We've run these switches on Porsche 962's at rough Sebring and not had a single false-trip. When tripped, they can be easily reset buy pressing down on the red button. It is a good safety feature to have.