Ford F-250 Super Duty (1999 year). Manual — part 7

•

(Panel) -Distributes outside air through the instrument panel

registers.

• OFF-Outside air is shut out and the fan will not operate.
•

(Panel and floor) -Distributes outside air through the instrument

panel registers and the floor ducts.

•

(Floor) -Allows for maximum heating. Distributes outside air

through the floor ducts.

•

(Floor and defrost) -Distributes outside air through the floor

ducts and the windshield defroster ducts.

•

(Defrost) -Distributes outside air through the windshield

defroster ducts. It can be used to clear ice or fog from the windshield.

Operating tips
• In humid weather, select

before driving. This will help to reduce

your windshield from fogging. After a few minutes, select any desired
position.

• To prevent humidity buildup inside the vehicle, don’t drive with the

climate control system in the OFF position.

• Don’t put objects under the front seat that will interfere with the

airflow to the back seats (if equipped).

• Remove any snow, ice or leaves

from the air intake area (at the
bottom of the windshield under
the hood).

• When placing objects on top of your instrument panel, be careful to

not place them over the defroster outlets. These objects can block
airflow and reduce your ability to see through your windshield. Also,
avoid placing small objects on top of your instrument panel. These
objects can fall down into the defroster outlets and block airflow and
possibly damage your climate control system.

Controls and features

25

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

• MAX A/C-Uses recirculated air to cool the vehicle. MAX A/C is noisier

than A/C but more economical and will cool the inside of the vehicle
faster. Airflow will be from the instrument panel registers. This mode
can also be used to prevent undesirable odors from entering the
vehicle.

• A/C-Uses outside air to cool the vehicle. It is quieter than MAX A/C

but not as economical. Airflow will be from the instrument panel
registers.

•

(Panel) -Distributes outside air through the instrument panel

registers. However, the air will not be cooled below the outside
temperature because the air conditioning does not operate in this
mode.

• OFF-Outside air is shut out and the fan will not operate. For short

periods of time only, use this mode to prevent undesirable odors from
entering the vehicle.

•

(Panel and floor) -Distributes outside air through the instrument

panel registers and the floor ducts. Heating and air conditioning
capabilities are provided in this mode. For added customer comfort,
when the temperature control knob is anywhere in between the full
hot and full cold positions, the air distributed through the floor ducts
will be slightly warmer than the air sent to the instrument panel
registers.

•

(Floor) -Allows for maximum heating by distributing outside air

through the floor ducts. However, the air will not be cooled below the
outside temperature because the air conditioning does not operate in
this mode.

•

(Floor and defrost) -Distributes outside air through the

windshield defroster ducts and the floor ducts. Heating and air
conditioning capabilities are provided in this mode. For added
customer comfort, the air distributed through the floor ducts will be
slightly warmer than the air sent to the windshield defroster ducts. If
the temperature is about 10°C (50°F) or higher, the air conditioner
will automatically dehumidify the air to reduce fogging.

•

(Defrost) -Distributes outside air through the windshield

defroster ducts. It can be used to clear ice or fog from the windshield.
If the temperature is about 10°C (50°F) or higher, the air conditioner
will automatically dehumidify the air to reduce fogging.

Controls and features

27

Operating tips
• In humid weather, select

before driving. This will reduce your

windshield from fogging. After a few minutes, select any desired
position.

• To prevent humidity buildup inside the vehicle, don’t drive with the

climate control system in the OFF position.

• Don’t put objects under the front seat that will interfere with the

airflow to the back seats (if equipped).

• Remove any snow, ice or leaves

from the air intake area (at the
bottom of the windshield under
the hood).

• If your vehicle has been parked with the windows closed during hot

weather, the air conditioner will do a much faster job of cooling if you
drive for two or three minutes with the windows open. This will force
most of the hot, stale air out of the vehicle. Then operate your air
conditioner as you would normally.

• When placing objects on top of your instrument panel, be careful to

not place them over the defroster outlets. These objects can block
airflow and reduce your ability to see through your windshield. Also,
avoid placing small objects on top of your instrument panel. These
objects can fall down into the defroster outlets and block airflow and
possibly damage your climate control system.

Do not place objects on top of the instrument panel, as these
objects may become projectiles in a collision or sudden stop.

Controls and features

28