ad blue GMC SIERRA 2001 Owner's Manual

3-2
Comfort Controls
Standard Comfort Controls
Fan Knob
The knob on the left side of the control panel adjusts the
fan speed. To increase airflow, turn the knob clockwise.
To decrease airflow, turn it counterclockwise. To turn
the fan off, turn the knob to OFF.
Temperature Knob
The middle knob on the control panel lets you select the
temperature of the air flowing into the passenger area.
Turn the knob clockwise toward the red area for warmer
air. Turn the knob counterclockwise toward the blue area
for cooler air.Mode Knob
The right knob on the control panel allows you to
choose the direction of air delivery.
VENT: This setting directs the air through the
instrument panel outlets.
BI-LEVEL: Air is delivered through the heater
floor outlets as well as the instrument panel outlets.
The air flow can be divided between VENT and
HEATER depending upon where the knob is placed
between the settings.
HEATER: This setting directs most of the
warmed air through the heater floor outlets, and the rest
of the air is divided between the windshield defroster
outlets and the side window defroster outlets.
BLEND: Airflow is delivered through the heater
floor outlets, the windshield defroster outlets and the
side window defroster outlets. The air flow can be
divided between HEATER and DEFROST depending
upon where the knob is placed between the settings.
DEFROST: This setting directs most air through
the windshield defroster outlets, side window defroster
outlets and some through the heater outlets.

3-3 Heater and Air Conditioning Comfort
Controls (If Equipped)
Fan Knob
The knob on the left side of the control panel adjusts the
fan speed. To increase airflow, turn the knob clockwise.
To decrease airflow, turn it counterclockwise. To turn
the fan off, turn the knob to OFF.
Temperature Knob
The middle knob on the control panel lets you select the
temperature of the air flowing into the passenger area.
Turn the knob clockwise toward the red area for warmer
air. Turn the knob counterclockwise toward the blue area
for cooler air.Mode Knob
The right knob on the control panel allows you to
choose the direction of air delivery.
PANEL: This setting directs the air through the
instrument panel outlets and the center floor console
(if equipped).
BI-LEVEL: Air is delivered through the
instrument panel outlets and center floor console outlets
(if equipped) as well as the heater floor outlets. The air
flow can be divided between PANEL and HEATER
depending upon where the knob is placed between the
settings. Pressing the A/C button while in this mode
causes cooler air to come out of the instrument panel
outlets and center floor console outlets (if equipped)
and warmer air to come out of the heater floor outlets.
HEATER: This setting directs most of the
warmed air through the heater floor outlets and center
floor console outlets (if equipped), as well as some
air through the windshield defroster outlets and side
window defroster outlets. If air from the center floor
console outlets is not desired, turn the vents off at
the console.

3-10
Rear Air Conditioning and Rear Heater
(If Equipped)
If your vehicle has the rear air conditioning and rear
heater system combination, controls are provided to
regulate temperature, location and speed of the airflow.
Front Control
To adjust the airflow speed, turn the fan control knob
located on the left side to the desired setting.
To activate the second seat control system, turn the fan
knob on the front overhead control to REAR.
To regulate the airflow location, adjust the right knob on
the control panel. Turn the knob clockwise for floor vent
airflow or counterclockwise for headliner vent airflow. Generally, the upper vents are used for air conditioning
and the floor vents for heating. The knob can be set to
any blend setting.
To adjust the air temperature, turn the temperature knob
on the center of the control panel.
For warmer air, turn the knob clockwise toward red.
For cooler air, turn the knob counterclockwise toward blue.
Rear Control
The rear control works just like the front control. It will
allow second seat passengers to adjust the controls as
they desire. To use the rear control, first turn the front
knob to REAR.

3-12 Air Conditioning
On hot days, open the windows long enough to let hot
air inside escape. This reduces the time it takes for your
vehicle to cool down. Then keep your windows closed
for the air conditioner to work its best.
The RECIRCULATION button allows the air inside
your vehicle to be recirculated. This setting helps to
maximize your air conditioner's performance and
your vehicle's fuel economy. This setting also cools air
the fastest and can be used to keep unwanted odors
and/or dust from entering the vehicle. When using the
air conditioner, turn off the RECIRCULATION
button after the vehicle reaches a comfortable interior
temperature. When the right knob on the control panel
is between HEATER and DEFROST, the recirculation
feature will not function to reduce window fogging.
The A/C button, below the mode knob, allows the
air coming into your vehicle to be cooled. This setting
is useful for normal cooling on hot days. When you use A/C with the RECIRCULATION button
pushed in, turn off recirculation as soon as the vehicle
reaches a comfortable interior temperature.
Maximum air conditioning performance is obtained by
pressing the A/C button, the RECIRCULATION button
and turning the temperature knob fully counterclockwise
to the blue area. This setting also cools air the fastest.
After the vehicle's interior reaches a comfortable
temperature, press the OUTSIDE AIR button to
place the air conditioning system in the normal mode.
Passenger Compartment Air Filter (If Equipped)
If your vehicle has air conditioning, it is equipped with
a passenger compartment air filter, which filters outside
air entering the vehicle. For information on replacing
the filter see ªPassenger Compartment Air Filterº in
the Index.

4-78
The six-wire harness contains the following
trailer circuits:

Yellow: Left Stop/Turn Signal

Dark Green: Right Stop/Turn Signal

Brown: Taillamps

White: Ground

Light Green: Back
-up Lamps

Light Blue: Center High
-Mounted
Stoplamp (CHMSL)
If you need to upgrade your vehicle to heavy
-duty
trailering, a brake controller harness and an underbody
harness with a seven
-pin universal heavy-duty trailer
connector are available from your dealer.Heavy
-Duty Trailer Wiring Package (If Equipped)
Your pickup may be equipped with the eight-wire trailer
towing harness. This harness with a seven
-pin universal
heavy
-duty trailer connector is attached to a bracket on
the platform hitch.*
* The Center High
-Mounted Stoplamp (CHMSL) wire
is tied next to the trailer wiring harness for use with a
trailer, slide
-in camper or cap.

4-79
The eight-wire harness contains the following
trailer circuits:

Yellow: Left Stop/Turn Signal

Dark Green: Right Stop/Turn Signal

Brown: Taillamps

White: Ground

Light Green: Back
-up Lamps

Light Blue: CHMSL

Red: Battery Feed

Dark Blue: Trailer Brake
A jumper harness for an electric trailer brake controller
and a trailer battery feed fuse are included with this
trailering package. (See ªInstrument Panel Jumper
Wiring Harnessº later in this section.)
If you need to tow a light
-duty trailer with a standard
four
-way round pin connector, an adapter connector is
available from your dealer.Camper/Fifth
-Wheel Trailer Wiring Package
(If Equipped)
The eight
-wire camper harness is located under the
front edge of the pickup box on the driver's side of the
vehicle, attached to the frame bracket. A connector will
have to be added to the wiring harness which connects
to the camper.
The eight
-wire harness contains the following
camper/trailer circuits:

Yellow: Left Stop/Turn Signal

Dark Green: Right Stop/Turn Signal

Brown: Taillamps

White: Ground

Light Green: Back
-up Lamps

Light Blue: Center High
-Mounted
Stoplamp (CHMSL)

Red: Battery Feed

Dark Blue: Trailer Brake
A jumper harness for an electric trailer brake controller
and a trailer battery feed fuse are included with this
trailering package. (See ªInstrument Panel Jumper
Wiring Harnessº later in this section.)