2002 GMC SAFARI air conditioning

3-2
Comfort Controls
This section tells you how to make your air system work
for you. Your comfort control system with air
conditioning uses ozone
-friendly refrigerant.
With these systems, you can control the heating,
cooling and ventilation in your vehicle. Your vehicle
also has a flow
-through ventilation system described
later in this section.
Heating System
If your vehicle does not have air conditioning, your
heater controls will look like this.Fan Knob
The fan know is located on the left of the control
panel. This control has four positions. To increase
airflow, turn the knob toward HI. To decrease airflow,
move it toward LO.
Temperature Knob
This knob is next to the fan knob. It controls the
temperature of the air flowing into your vehicle. Turn
the knob clockwise for warmer air. Turn the knob
counterclockwise for cooler air.
Function Knob
This knob is on the right of the temperature knob.
The function knob allows you to choose the direction of
air delivery.
OFF: This setting turns the system off.
(Vent): The air comes out at the vents on your
instrument panel.

3-3
(Bi-level): With this setting, the outside air comes
out both the instrument panel vents and floor ducts.
Adjust the temperature knob for warmer or cooler air.
(Floor): Most of the air comes out near the floor.
The rest comes out from the defroster vents under the
windshield and at the front side windows.
(Blend): With this setting, the outside air comes
out both the floor ducts and defroster vents. Adjust the
temperature knob for warmer or cooler air.
DEF (Defrost): This setting operates the defroster.
Most of the air comes out near the windshield, with
some going to the floor ducts and front side windows.
Heating/Air Conditioning System
(If Equipped)
If your vehicle has air conditioning, your heating/air
conditioning controls will look like this.
Fan Knob
The fan knob is located on the left of the control panel.
This knob has four positions. To increase airflow,
turn the knob toward HI. To decrease airflow, move it
toward LO.

3-4
Temperature Knob
This knob is next to the fan knob. It controls the
temperature of the air flowing into your vehicle. Turn
the knob clockwise for warmer air. Turn the knob
counterclockwise for cooler air.
Function Knob
This knob is located on the right side of the temperature
knob. The function knob allows you to choose the
direction of air delivery.
OFF: This setting turns the system off.
MAX A/C (Maximum Air Conditioning): This setting
cools the air the fastest, by recirculating the inside air.
A/C (Air Conditioning): This setting brings in outside
air, cools and dehumidifies it.
(Bi-Level): This setting brings in outside air and
blows it out through the floor ducts and the instrument
panel vents. If you move the temperature knob between
hot and cold, cooler air will come out of the upper vents
while warmer air comes out of the floor ducts. The air
conditioning compressor may operate in this setting to
cool the air.
(Vent): The air comes out at the vents on your
instrument panel. The air conditioning compressor will
not run in this position. Adjust the temperature knob for
warmer or cooler air.
(Floor): Most of the air comes out near the floor.
The rest comes out from the defroster vents under the
windshield and at the front side windows.
(Blend): With this setting, the outside air comes
out of both the floor ducts and defroster vents. Adjust
the temperature knob for warmer or cooler air. The air
conditioning compressor may operate in this setting to
dehumidify the air.
DEF (Defrost): This setting operates the defroster.
Most of the air comes out near the windshield, with
some going to the floor ducts and front side windows.
The air conditioning compressor may operate in this
setting to dehumidify the air.

3-5 Rear Heating System (Option)
You may have the optional rear heater. The three-speed
fan thumbwheel is to the right of the radio. Turn the
thumbwheel toward HIGH for higher airflow in the
rear area. Turn the thumbwheel to OFF to turn the
system off.
Rear Air Conditioning System (Option)
You may have rear air conditioning. The rear air
conditioning thumbwheel is located to the right of the
heater controls. Turn the thumbwheel toward HIGH for
higher airflow in the rear area. Turn the switch to OFF
to turn the system off.

3-6 Air Conditioning
Before using your vehicle's air conditioning, open the
windows to clear the vehicle of hot air. This reduces the
time it takes for your vehicle to cool down. Then keep
your windows closed for the air conditioner to work at
its best.
You can use MAX A/C with the temperature knob in
the blue area when it's really hot outside and you need
to cool the inside air quickly. MAX A/C lets in only a
little air from the outside.
If you first use MAX A/C, you can then use A/C with
the temperature knob in the blue area as soon as the
vehicle has cooled down, so outside air will be going
through your vehicle.
If your vehicle has rear air conditioning, setting it on LOW
may enhance the front air conditioning performance by
allowing trapped refrigerant in the rear lines to circulate.
The rear air conditioning system will only send cooled
air if the front system is on. It can still be used to
circulate air, even if the front system is off.
When the air conditioning, defrost or blend is on, you
may notice a slight increase or decrease in engine speed,
due to compressor operation. This is normal because the
system is designed to cycle the compressor on and off to
maintain the desired temperature.
Heating
On cold days, use the floor setting with the temperature
knob in the red area. Outside air will be brought in
through the floor ducts. The heater works best if you
keep your windows closed while using it.
If you use the optional engine coolant heater before
starting your engine, your heating system will produce
warmer air faster to heat the passenger compartment in
cold weather. See ªEngine Coolant Heaterº in the Index.
Defrosting
Use defrost to remove fog or ice from the windshield
quickly in extremely cold conditions. The temperature
knob should be in the red area and the fan control
toward high. The air conditioning compressor may
operate in this setting to dehumidify the air.
The blend setting is useful for cold weather with a large
number of passengers or very humid conditions to help
keep the windshield clear.

3-8 Ventilation System
For mild outside temperatures when little heating or
cooling is needed, use the vent setting to direct outside
air through your vehicle. Air will flow through the
instrument panel vents.
Your vehicle's flow
-through ventilation system supplies
outside air to the inside of your vehicle when it is
moving. With the side windows closed, air will flow into
the front air inlet grilles at the base of the windshield,
through the vehicle and out the rear air exhaust valve.
Outside air will also enter the vehicle when the heater
or the air conditioning compressor is running.
Your vehicle has air vents near the center and on the
sides of the instrument panel that allow you to adjust the
direction and the amount of airflow inside the vehicle.
Move the dial on the vent up or down to direct airflow
to your preference. Increase or reduce the amount of
airflow by opening and closing the louvers. The vents
turn to direct the airflow from side to side.

3-9
When you close a vent, it will increase the flow of air
coming out of any vents that are open.
If you have rear heating or rear air conditioning, you
will have adjustable vents in the rear of the vehicle to
help direct the airflow. The rear air conditioning vents
are located in the headliner at the rear of the vehicle.
The rear heating vents are located next to the second and
third seat on the driver's side of the vehicle, near the
floor. You can move the vents to direct the flow of air,
or close the vents altogether. When you close a vent, it
will increase the flow of air coming out of any vents that
are open.Ventilation Tips

Keep the hood and front air inlet free of ice, snow or
any other obstruction (such as leaves). The heater
and defroster will work far better, reducing the
chance of fogging the inside of your windows.

When you enter a vehicle in cold weather, turn the
fan to HI for a few moments before driving off.
This helps clear the intake ducts of snow and
moisture and reduces the chance of fogging the
inside of your windows.

Keep the air path under the front seats clear of
objects. This helps air to circulate throughout
your vehicle.

6-71
Relay Usage
A/C Relay
(Rear Heat
and A/C)Rear Heat and
Air Conditioning
Upfitter
-ACCY
RelayUpfitter Accessory
Starter
Enable RelayStarter
A/C Enable Relay Air Conditioning
Headlamps Relay Headlamps
Fuel Pump Relay Fuel Pump
Fuse/Circuit
BreakerUsage
UPFITTER
-BATT Upfitter Battery Power Stud,
Trailer Wiring Harness
UPFITTER
-ACCY Upfitter Accessory Relay
Spare Not used
Spare Not used
Spare Not used
ECM
-1B Fuel Pump Relay and Motor,
VCM, Oil Pressure Switch/SenderFuse/Circuit
BreakerUsage
HORN Horn Relay and Horn
A/C COMP A/C Enable Relay and
Compressor
RR HTR/AC Rear Heater and A/C
ATC Active Transfer Case
-L Van
FRT HVAC Front Heater and A/C
ENG
-I Oxygen Sensors, Camshaft
Position Sensor, Mass Air Flow
Sensor, Evaporative Emission
Canister Vent Solenoid
IGN
-E A/C Enable Relay Coil
ECM
-I Fuel Injectors 1-6, Crankshaft
Position Sensor, VCM,
Coil Driver Module (EST),
Ignition Coil
Blank Not Used
RH HDLMP Right Headlamp
LH Headlamp Left Headlamp
Blank Not Used
Blank Not Used