Cut-Off/Inertia Switch
Some models with fuel injection use a inertial switch (Ford Motor Co.) to stop the fuel pump if the engine stops or a collision occurs. The cut-off switch contacts close when oil pressure is above 4 psi (.3 kg/cm2 ). This provides a secondary power feed to the fuel pump if the fuel pump relay fails. The cut-off switch is located in the oil pressure sending unit.
The inertia (may also be called shut-off) switch contacts are usually closed to complete the fuel pump circuit. If inertia switch is triggered the White reset button will pop up. Inertia switches are located in various positions in rear sections of the vehicle. To reset inertia switch, push White reset button down.