To find it, you'll likely need to:
* Feel around: Run your hand along the underside of the dashboard on the passenger side. It's often a small, square or rectangular box.
* Look for a label: It might have a label indicating "Inertia Switch" or a similar description.
* Consult your owner's manual: The owner's manual should have a diagram showing the location of the inertia switch (and other fuses and relays).
If you can't find it after searching these areas, a detailed diagram in a repair manual for your specific year and model might be helpful. You can often find these manuals online or at auto parts stores.