Inertia Fuel Shutoff Switch: Description and Operation

PURPOSE
The Inertia Fuel Shut-off (IFS) switch is used in conjunction with the electric fuel pump. The purpose of the IFS switch is to shut off the fuel pump if a collision occurs. The collision does NOT have to be great to trigger the switch. A parking lot bump or large pot hole could set it.

Typical Inertia Fuel Shutoff (IFS) Switch:

OPERATION
The IFS 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 which opens the electrical contacts of the switch and shuts off the electric fuel pump. Once the switch is open, it must be manually reset before restarting the vehicle.