Ford 1998 Windstar Owner's Manual page 218

To return the transaxle to the normal Overdrive operation, press
the OVERDRIVE ON/OFF button again. Use this button to
select Overdrive or Overdrive Off whenever you drive your
vehicle.
The transaxle will be in the "overdrive on" mode when the
vehicle is started even if the O/D OFF mode was selected when
the vehicle was last shut off.
NOTE: If the O/D OFF indicator light is flashing on and off
repeatedly when the vehicle is started, there is a
transaxle electronic system malfunction. Contact your
dealer as soon as possible.
When to use 2 (Second)
Use 2 (Second) when driving on slippery roads or to provide
additional engine braking on downgrades. This position
provides Second and First gear operation only.
When to use 1 (First)
Use 1 (First) to provide maximum engine braking on steep
downgrades. Upshifts from First can be made by manually
shifting to 2 (Second) or j (Overdrive). 1 (First) gear provides
only first gear operation. If you select First while driving at
higher speeds, the transaxle will shift to 2 (Second), and then
downshift to 1 (First) after the vehicle decelerates to the proper
speed.
Parking
Always come to a complete stop before you shift into P (Park).
This position locks the transaxle and prevents the front wheels
from turning. To securely latch the gearshift in the P (Park)
position, pull it toward you, push it completely
counterclockwise against the stop, and then push it toward the
instrument panel.
Driving
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