Ford 1999 Windstar Owner's Manual page 92

Controls and features
Unlocking the doors
• 3–button remote
• 4–button remote
• 5–button remote
Press this control to unlock the driver door and disarm the anti-theft
system (if equipped). The interior lamps will illuminate.
Press the control again within three seconds to unlock all doors and
liftgate. If the control is pressed a third time within three seconds, the
vehicle will chirp the horn once if all doors/hood are closed or twice if
any door/hood is open.
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