Ford Mercury Villager 1997 Owner's Manual page 78

If the rear seat climate control lever is set in any of the fan speed
positions (1-4), air will be discharged from the rear seat vents
at the corresponding speed. Rear seat passengers can choose
airflow to be distributed out of the upper or lower vents by using
the vent selection switch on the rear climate control panel. The
air temperature from the rear climate control system will be
automatically controlled by the front ATC system. Rear seat
passengers cannot control fan speed or air temperature by using
the temperature control knobs on the rear climate control
panel.
If the rear seat climate control lever is set in the REAR position,
the front ATC system will not control the rear climate control
system. Rear seat passengers can control fan speed, upper or lower
air distribution, and temperature control from the rear system
by using the rear climate controls.
Rear seat climate control system panel
74