1999 CHEVROLET CORVETTE air conditioning

yellowblue
3-9
If the system is in FRONT defrost when you shut the
engine off, it will restart in FRONT defrost unless the
engine is off for longer than 40 minutes. If the engine is
off longer than 40 minutes, the system will restart in the
operating mode you had set prior to FRONT defrost.
The air conditioning cools and dehumidifies air coming
into the vehicle. It also operates in defrost to help
remove moisture from the vehicle. The air conditioning
does not operate at temperatures below approximately
35
F to 40
F (2
C to 4
C). If the system is operating in
the AUTO mode, turning the air conditioning off will
delete AUTO from the digital display and show current
mode and fan settings. The AUTO button must be
pressed to return to the automatic mode operation.
See ªRear Window Defoggerº later in this section for
more information.Sensors
The Automatic Electronic Dual Climate Control
System uses several sensors to control operation and
display information.
Solar Load Sensor
This sensor is located on the top right side of the
defroster grille. The defroster grille is on the top of the
instrument panel.
The sensor monitors the sun's solar radiation and uses
this information as part of the automatic climate control
system when operating in the AUTO mode.
Be careful not to put anything over the sensor. When
covered, the sensor cannot compensate for changes in
the amount of heat the vehicle is absorbing from the sun.

yellowblue
3-10
Outside Air Temperature Sensor
This sensor is located in the air intake under the front
bumper of the vehicle. Information from this sensor
is used for the outside air temperature readings shown
on the digital display for the automatic climate
control system.
If the outside temperature goes up, the displayed
temperature will not change until:

The vehicle's speed is above 20 mph (32 km/h) for
one and a half minutes.

The vehicle's speed is above 45 mph (72 km/h) for
one minute.
These delays help prevent false readings. If the
temperature goes down, the outside temperature display
is updated immediately.
If the vehicle has been turned off for more than three
hours, the current outside temperature will be shown
when you start the vehicle. If it has been turned off for
less than three hours, the temperature will be recalled
from the previous vehicle operation.Inside Temperature Sensor
This sensor is located to the left of the ignition switch.
The automatic climate control system uses this sensor to
receive information, so if you block or cover it, the
system will not function properly.
Air Conditioning
On very hot days, the vehicle will cool down more
quickly and economically if you open the windows long
enough to let hot inside air escape. Then keep the
windows closed in order to allow the air conditioning to
work best. Maximum cooling will occur when the
recirculate setting is operating, airflow direction is in the
upper mode, and the temperature control knob
(on a manual climate control system) is turned all the
way to the blue area. These settings will be selected
by the Automatic Electronic Dual Climate Control
System if operating in AUTO when maximum cooling
is required.
When the air conditioning is on, you may sometimes
notice slight changes in the vehicle's engine
performance and power. This is normal. The system is
designed to help fuel economy while maintaining the
desired cooling level.

yellowblue
3-11
The air conditioning removes moisture from the air, so
you may notice water dripping from under the vehicle
when it is idling or after it has been turned off.
This is normal.
Heating
The heater works best if you keep the windows closed.
Maximum heating will occur when airflow direction is
in the lower mode and the temperature control knob
(on a manual climate control system) is all the way in
the red area. These settings will be selected by the
Automatic Electronic Dual Climate Control System if
operating in AUTO when maximum heating is required.
The BI
-LEVEL setting is designed for use on sunny
days when the air is only moderately warm or cool.
On days like these, the sun may adequately warm your
upper body, but your lower body may not be warm
enough. The BI
-LEVEL setting will direct cooler
airflow to your upper body and warmer air to the
floor area.
If you have the optional engine coolant heater and use it
during cold weather 0
F (
-18
C) or lower, the heating
system will provide heat more quickly because the
coolant is already warmed. See ªEngine Coolant Heaterº
in the Index.
Defogging and Defrosting
To rapidly defrost the windshield, the FRONT defrost
mode (Automatic Electronic Dual Climate Control
System) or defrost mode (manual control system)
should be used and the fan speed should be adjusted to
the highest speed. With the manual control system, turn
the temperature control knob all the way to the red area.
To keep the windshield clear and provide heated air to
the floor area of the vehicle, use the DEFOG setting.
Your vehicle is equipped with side window defogger
vents located near the side rearview mirrors.
Rear Window Defogger
REAR: This button turns the rear defogger and the
optional heated outside mirrors on. The light on the
button will come on when operating. The system
automatically shuts off after approximately 10 minutes.
If further defogging is desired, press the button again
and it will operate for about five more minutes.
The rear window defogger operates only when the
engine is running.

6-
yellowblue
6-1
Section 6 Service and Appearance Care
Here you will find information about the care of your vehicle. This section begins with service and fuel information,
and then it shows how to check important fluid and lubricant levels. There is also technical information about your
vehicle, and a part devoted to its appearance care.
6
-2 Service
6
-3 Fuel
6
-6 Filling Your Tank
6
-9 Checking Things Under the Hood
6
-12 Engine Oil
6
-16 Engine Air Cleaner/Filter
6
-18 Automatic Transmission Fluid
6
-19 Manual Transmission Fluid
6
-20 Hydraulic Clutch
6
-21 Rear Axle
6
-22 Surge Tank Pressure Cap
6
-23 Engine Coolant
6
-26 Power Steering Fluid
6
-27 Windshield Washer Fluid
6
-29 Brakes
6
-32 Battery
6
-33 Bulb Replacement
6
-38 Windshield Wiper Blade Replacement
6
-41 Tires6
-52 Lifting Your Corvette
6-56 Appearance Care
6
-56 Cleaning the Inside of Your Vehicle
6
-59 Cleaning a Removable Roof Panel
6
-60 Cleaning the Outside of Your Vehicle
6
-61 Cleaning Your Convertible Top
6
-62 Cleaning Aluminum Wheels
6
-62 Cleaning Tires
6
-62 Finish Damage
6
-63 Underbody Maintenance
6
-64 GM Vehicle Care/Appearance Materials
6
-65 Vehicle Identification Number (VIN)
6
-65 Service Parts Identification Label
6
-66 Electrical System
6
-74 Replacement Bulbs
6
-74 Capacities and Specifications
6
-76 Air Conditioning Refrigerants
6
-76 Normal Maintenance Replacement Parts

yellowblue
6-72
Fuse Usage
7 Selective Real Time Damping
8 Headlamp Low Beam Right
9 Headlamp High Beam Right
10 Headlamp Low Beam Left
11 Horn
12 Headlamp High Beam Left
13 Fuel Pump
14 Cooling Fan
- Ignition 3
15 Oxygen Sensor
16 Powertrain Control Module
17 Throttle Control
18 Injector 2
19 Engine Ignition
20 BlankFuse Usage
21 Blank
22 Injector 1
23 Powertrain Control Module
24 Air Conditioning
25 Blank
26 Blank
27 Spare
28 Spare
29 Spare
30 Spare
31 Spare
32 Spare
33 Micro Relay
- Air Pump
34 Micro Relay
- Air Conditioner and
Clutch

yellowblue
6-74
Replacement Bulbs
High-Beam Headlamp 9005. . . . . . . . . . . . . . . . . . . .
Low
-Beam Headlamp 9006. . . . . . . . . . . . . . . . . . . .
Front Parking/Turn Signal 3157 NAK. . . . . . . . . . . . .
Back
-Up 2057. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Sidemarker 194. . . . . . . . . . . . . . . . . . . . . . . . .
Rear Sidemarker 194. . . . . . . . . . . . . . . . . . . . . . . . .
Rear Stop/Tail and Turn Signal 3057. . . . . . . . . . . . .
For any bulb replacements or procedures not listed here,
please consult your dealer.
Capacities and Specifications
The following approximate capacities are given in
English and metric conversions.
Please refer to ªRecommended Fluids and Lubricantsº
in the Index for more information.
Air ConditioningSee the refrigerant . . . . . . . . . . . .
information label under the hood.
Automatic Transmission
Drain and Refill 5.0 quarts (4.7 L). . . . . . . . . . . . . .
Overhaul 10.8 quarts (10.2 L). . . . . . . . . . . . . . . . .
Coolant System
With M30 Automatic
Transmission 12.6 quarts (11.9 L). . . . . . . . . . . .
With MM6 Manual
Transmission 12.9 quarts (12.2 L). . . . . . . . . . .

yellowblue
6-76
Air Conditioning Refrigerants
Not all air conditioning refrigerants are the same. If the air
conditioning system in your vehicle needs refrigerant, be
sure the proper refrigerant is used. If you're not sure, ask
your dealer.
Normal Maintenance
Replacement Parts
Air Cleaner FilterA917C . . . . . . . . . . . . . . . . . . . . . .
Battery78A
-72H . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant Surge Tank CapGM Part No. 10296465 . . .
15 psi (105 kPa)
Engine Oil FilterPF44 . . . . . . . . . . . . . . . . . . . . . . . .
PCV Valve799C . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.060 inch (1.524 mm)
Spark Plug41
-931 (0.60 inch Gap) . . . . . . . . . . . . .
ThermostatGM Part No. 12555717 . . . . . . . . . . . . .
or equivalent
Windshield Wiper Blade
Length 22 inches (55.9 cm). . . . . . . . . . . . . . . . . . . .
Type 9 mm x 3 mm Shepherd's Hook. . . . . . . . . . . .
Vehicle Dimensions
Wheelbase104.5 inches (265.4 cm) . . . . . . . . . . . . . .
Tread
Front 62.1 inches (157.7 cm). . . . . . . . . . . . . . . . . .
Rear 62.0 inches (157.4 cm). . . . . . . . . . . . . . . . . . .
Length179.7 inches (456.4 cm) . . . . . . . . . . . . . . . . .
Width73.6 inches (186.9 cm) . . . . . . . . . . . . . . . . . . .
Height47.7 inches (121.1 cm) . . . . . . . . . . . . . . . . . .

yellowblue
7-18 Engine Cooling System Inspection
Inspect the hoses and have them replaced if they are
cracked, swollen or deteriorated. Inspect all pipes,
fittings and clamps; replace as needed. Clean the outside
of the radiator and air conditioning condenser. To help
ensure proper operation, a pressure test of the cooling
system and pressure cap is recommended at least once
a year.
Rear Axle Service
Check the gear lubricant level in the rear axle and add if
needed. See ªRear Axleº in the Index. A fluid loss may
indicate a problem. Check the axle and repair it
if needed.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook
-up, binding, leaks, cracks,
chafing, etc. Inspect disc brake pads for wear and rotors
for surface condition. Inspect other brake parts,
including calipers, parking brake, etc. You may need to
have your brakes inspected more often if your driving
habits or conditions result in frequent braking.