1996 Ford Crown Victoria Owner's Manual - Page 221

Preparing to Change the Tire 1. Make sure that your vehicle will not move or roll. Put the gearshift in P (Park). Set the parking brake and block the wheel that is diagonally opposite the tire that you are changing. When one of the back wheels is off the ground, the transmission alone will not prevent the vehicle from moving or slipping off the jack, even if the vehicle is in P (Park). To prevent the vehicle from moving when you change a tire, be sure the parking brake is set, then block the wheel (both directions) that is diagonally opposite (other side and end of the vehicle) to the tire being changed. RWARNING If the vehicle slips off the jack, you or someone else could be seriously injured. Turn off the air suspension switch (if equipped) prior to jacking. RWARNING On vehicles equipped with Air Suspension, turn OFF the Air Suspension switch prior to jacking, hoisting or towing your vehicle. The air suspension switch - located in the trunk 205