GMC chervolet camaro 1999 Service Manual page 108

HVAC HVAC System - Manual 1-17
Functional Check
Step Action
Normal Result(s) Abnormal Result(s)*
1. Place the mode control knob in
• The blower motor speed is OFF. • Airflow from the heater, A/C, or
the OFF position.
• There is no airflow from the
defroster outlets.
2. Place the temperature control heater outlets. • Apply vacuum to each vacuum
knob in the COLD (blue)
• There is no airflow from the A/C
line individually (except black
position.
outlets.
and orange)
1
3. Place the blower motor knob in
• There is no air flow from the
• If air flows out the outlets repair
the LOW fan position.
defroster outlets.
or replace the actuator linkage
and/or air valve (door).
• Blower motor runs.
• Refer to Air Delivery Improper,
or Blower Motor Inoperative at
Any Speed
1. Place the mode control knob in • The blower motor speed • Airflow from the heater or
the MAX A/C setting.
is LOW. defroster outlets. No airflow from
2. Place the temperature control
• There is no airflow from the
the A/C outlets.
knob in the COLD setting.
heater outlets. • Temperature does not change.
3. Place the blower motor knob in
• There is airflow from the A/C
• No blower motor speed change.
the LOW setting. outlets.
• Blower motor speed inop.
2
• There is no air flow from the
• Refer to Cooling Insufficient -
defroster outlets.
AIC Inoperative, System
• Temperature from the center Performance Test, Air Delivery
A/C outlet should drop 11 °C Improper, Temperature Control
(20°F) from the temperature Inoperative or Blower Motor
outside the vehicle. Inoperative at Any Speed.
• Engagement of the detent is felt
in each mode.
1. Place the mode control knob in
• The blower motor speed is LOW
• There is airflow from the heater
the MAX A/C setting.
to HIGH. and/or defroster outlets.
2. Place the temperature control
• There is no airflow from the
• There is no airflow from the A/C
knob in the COLD setting. heater outlets. outlets.
3. Place the blower motor knob in • There is airflow from the A/C • Temperature does not change.
the LOW to HIGH setting. outlets.
• No blower motor speed change.
• There is no air flow from the
• Blower motor speed inop.
defroster outlets.
• Refer to Cooling Insufficient -
• Temperature from the center
A!C Inoperative, System
A/C outlet should drop 11 °C
Performance Test, Air Delivery
3
(20°F) from the temperature
Improper, Temperature Control
outside the vehicle.
Inoperative or Blower Motor
• A noticeable blower speed Inoperative at Any Speed.
increase occurs from the
following settings:
• LOW
• MEDIUM LOW
• MEDIUM HIGH
• HIGH
• The outlets hold their position
during high blower motor speed
and are moveable by hand.