There isn't a readily accessible, easily identifiable "fuel cut-off switch" on a 2004 Ford Freestar like you might find on some other vehicles (e.g., a readily accessible switch in the passenger compartment). Fuel shutoff in a modern car like that is typically handled through the vehicle's electrical system and computer controls. Disconnecting the battery is the closest equivalent for an emergency shutoff.
If you're experiencing a fuel-related issue, contacting a qualified mechanic is recommended.
