To find it, you might need to:
* Feel around: Carefully run your hand along the underside of the dashboard on the passenger side. The switch is usually a small, square or rectangular box.
* Look for wiring: Follow the fuel pump wiring harness; the inertia switch is often located near where the harness enters the passenger compartment.
* Consult your owner's manual: If you still can't find it, your owner's manual might have a diagram showing its location.
* Check online forums: Searching online forums specific to 1991 Ford Rangers might yield pictures or descriptions from other owners who have located theirs.
Remember to be careful when searching, avoid damaging any wires or other components.