1991 HONDA CIVIC control arm

Heating and Cooling

The vents, heater and air conditioner are combined in one system;
adjusting four basic controls to different settings can provide a full range of interior temperatures for safe and comfortable driving.
Air conditioner: optional

Ventilation

The flow-through ventilation system can provide fresh air to the
interior when the car is moving or stopped, even with the windows

closed.

NOTE:

For proper air flow, the flow-through vents must not be covered.Keep the air inlet at the base of the windshield free of leaves or
other debris.
You can adjust the controls to direct cool or warm outside air
throughout the car for defogging windows, heating, or cooling by turning on the fan.

(cont'd)

AIR OUTLET

AIR INLETProCarManuals.comMain Menu s t

Fan Switch

Switch the fan to low ( 1 ), medium ( 2 ), medium high ( 3 ) or high
speed ( 4 ), to circulate warm, cool, or outside air, depending on
where the temperature control dial and function levers are set.

Function Lever

Slide the lever right or left to direct outside air or recirculated (inside) air to and from the heater, air conditioner and vents.

Temperature Control Dial
Turn the dial clockwise to make air warmer with the function lever in any position.

Air Conditioner Switch (optional)

With the fan on, push the A/C switch to operate the air conditioner;
the indicator light will come on. Push the switch again to turn the air conditioner off.

(cont'd)

What the Controls Do:

TEMPERATURECONTROL DIAL RECIRCULATION

LEVER
FAN SWITCH

FUNCTION LEVER AIR CONDITIONER SWITCH
and INDICATOR LIGHT

(optional)ProCarManuals.comMain Menu s t

Heating and Cooling (cont'd)
Recirculation Lever
Sliding the lever from the position to the position
shuts off outside air and recirculates the air inside the car. If the
heater or air conditioner is on, and you want to warm up or cool
down the interior more quickly, or keep smoke or dust out of the car without losing the heat or cool function, simply slide the lever to the position.

NOTE:
The windows may become fogged if the system is in the po-
sition for an extended period of time with the air conditioner off. As soon as the interior is warmed, slide the lever to the posi-

tion.

How to Use the Controls

To Ventilate

Turn the temperature control dial counterclockwise, slide the recirculation lever to the position and the function lever to
the position. Switch the fan on and outside air will flow
through the corner and center vents. To change air distribution,
slide the function lever to the position, and outside air will
also flow from the floor level outlet at the heater.
TEMPERATURE
CONTROL DIAL RECIRCULATION
LEVER
FAN SWITCH

FUNCTION LEVER AIR CONDITIONER
SWITCH (optional)ProCarManuals.comMain Menu s t

To Cool (with optional air conditioner)

To cool the car down quickly, slide the recirculation lever to the
position, start the engine, turn the temperature control dial
counterclockwise all the way, switch the fan to high ( 4 ), push the
A/C button in, and open the window briefly.
Then close the windows and corner vents, slide the function lever to the position and the recirculation lever to the po-
sition so inside air will recirculate to the air conditioner for maximum

cooling.

When the interior has cooled sufficiently, switch the fan to the desired speed, then slide the recirculation lever to to direct
fresh (outside) air to the air conditioner.
When using the air conditioner in heavy traffic, or while driving up long hills, watch the coolant temperature gauge: if the needle movesnear the "H" end of the scale, turn the air conditioner off bypushing the A/C button; leave it off until the needle goes back into
the middle of the scale.

(cont'd)ProCarManuals.comMain Menu s t

Heating and Cooling (cont'd)
To Heat
Switch the fan on, turn the temperature control dial clockwise, slide the function lever to the position and the recirculation lever
to the position, and warmed (outside) air will begin flowing

from the floor outlets.

To warm up the interior quickly, slide the recirculation lever to the
position so inside air will recirculate to the heater.

The windows may become fogged if the system is in the po-

sition for an extended period of time. As soon as the interior is
warmed, slide the lever to the position.

To Dehumidify (with optional air conditioner)
Because an air conditioner dehumidifies as it works, you can use it
in cool or cold weather to help defog the windows. Just switch the
fan on, push the A/C button, select the desired function and adjust
the temperature control dial to a comfortable setting.
NOTE:
This setting is desirable for most operating conditions in ambient temperatures above approximately 32°F (0°C).ProCarManuals.comMain Menu s t

To Defrost

To defrost or defog the windshield and door windows, turn the

temoerature control dial clockwise, slide the function lever to the
(defrost) position, and switch the fan on.
If there is actual frost on the windows, first select the posi-

tion.
If the windows are fogged, select the position. Warmed air
will then flow from the windshield and side defroster vents.

To Turn Everything OFF
Slide all levers to the left, turn the temperature control dial
counterclockwise all the way, and push the A/C switch off.
NOTE:
This setting should only be used in cold weather for the first fewminutes of driving to prevent cold air from blowing into the cabin.
Under normal operating conditions, the fan should always be kept
ON to prevent the accumulation of stale air in the system.ProCarManuals.comMain Menu s t

If the Sunroof Won't Close
The sunroof can be closed manually, if the control switch will not close it.
1. Remove the round plug near the rear center of the headliner.
2. Insert the sunroof wrench (from.
the tool kit) into the socket.

SUNROOF

WRENCH

3. Turn the wrench counterclockwise until the roof closes and seats into its locked position (about ten turns).

4. Replace the plug.

Maintenance
Periodically pour a little water down the drain holes to make sure
they are not plugged. If they are free, water should drop on the
ground behind each front wheel.

CAUTION:

Do not put weight on the sunroof or force it open or closed, you
may damage the mechanism.
DRAIN HOLESSOCKET

Remove

plugProCarManuals.comMain Menu s t

For proper operation of your car's emission controls, your engine is

designed to use unleaded fuel only.

CAUTION:
Using leaded or even low-lead gasoline could damage some of your
emission controls, and also void their coverage under the emission
controls warranty.
Use gasoline from pumps labeled unleaded, with a pump octane
number of 86 or higher. The pump octane number is an average of
the Research (R) octane and Motor (M) octane numbers. Use of a lower octane gasoline can cause persistent, heavy "spark knock" (ametallic rapping noise), which can lead to engine damage if severe.
CAUTION:
If you notice steady spark knock while holding a steady speed on a
level road, try changing brands of gasoline. If the spark knock persists, consult your Honda dealer. Failure to do so is considered
misuse, and misuse is not covered under the New Car Warranty.
Occasionally you may notice light spark knock while accelerating or
driving up hills. This is no cause for concern, it simply means your
engine is running at its most economical.
Gasoline Containing AlcoholIf you decide to use a gasoline containing alcohol ("gasohol"), be
sure its octane rating is at least as high as that recommended for
unleaded gasoline. There are two types of "gasohol": that
containing ethanol, and that containing methanol. Do not use
gasohol that contains more than 10% ethanol. Do not use gasoline
containing methanol (methyl or wood alcohol) that does not also contain cosolvents and corrosion inhibitors for methanol. Never use
gasoline containing more than 5% methanol, even if it has cosolvents and corrosion inhibitors.

NOTE.
Fuel system damage or vehicle performance problems resulting
from the use of such fuels is not covered under the new car warranties. Honda cannot endorse the use of fuels containing methanol since evidence of their suitability is as yet incomplete. Before purchasing fuel from an unfamiliar station, try to confirm
whether the fuel contains alcohol, of what kind, and how much. If
you notice any undesirable operating symptoms after using a
gasoline that contains alcohol; or one that you think contains alcohol, switch to an unleaded gasoline, as recommended above.
GasolineProCarManuals.comMain Menu s t