Inertia Fuel Shutoff Switch: Description and Operation

Typical Inertia Fuel Shut-Off Switch:

The inertia switch is used to shut the fuel pump "OFF" in the event of a collision. The inertia switch consists of a steel ball held in place by a magnet. When a sharp impact occurs, the ball breaks loose from the magnet, rolls up a conical ramp and strikes a target plate. This opens the electrical contacts of the switch and disrupts power to the electric fuel pump. The engine will quit running a few seconds after the fuel pump loses power. The inertia switch must then be manually reset before the engine can be restarted.