FORD 1999 F-350 - Manual (Page 26)

Do not place objects on top of the instrument panel, as these
objects may become projectiles in a collision or a sudden stop.
Manual heating and air conditioning system (if equipped)
Fan speed control
Controls the volume of air circulated
in the vehicle.
Temperature control knob
Controls the temperature of the
airflow inside the vehicle.
Mode selector control
Controls the direction of the airflow
to the inside of the vehicle.
The air conditioning compressor will operate in all modes except
(Panel) and (Floor). However, the air conditioning will only
function if the outside temperature is about 10°C (50°F) or above.
Since the air conditioner removes considerable moisture from the air
during operation, it is normal if clear water drips on the ground under
the air conditioner drain while the system is working and even after you
have stopped the vehicle.
Under normal conditions, your vehicle’s climate control system should be
left in any position other than MAX A/C or OFF when the vehicle is
parked. This allows the vehicle to “breathe” through the outside air inlet
duct. In snowy or dirty conditions, leave the mode selector in the OFF
position.
OFF
A/C
MAX
A/C
OFF
A/C
MAX
A/C
Controls and features
26