GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Lumina 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 HVAC Air Delivery System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Start the engine.
  2. Place the heater-A/C control mode selector in the VENT position.
  3. Place the blower control in a medium speed.

Air flows from the panel outlets.

Vacuum System

2

Place the heater-A/C control in the BI-LEVEL position.
    • Air flows from the panel and the floor outlets.
    • There is a slight air flow from the defrost outlets.

Vacuum System

3

Place the heater-A/C control in the HEATER position.
    • Air flows from the floor outlets.
    • There is a slight air flow from the defrost outlets.

Vacuum System

4

Place the heater-A/C control in the MAX position.
    • Air flows from the panel outlets.
    • Inside air is recirculated through the cooling system.

Vacuum System

5

Place the heater-A/C control in the DEFROST position.
    • Air flows from the defrost outlets.
    • There is a slight air flow from the floor outlets.

Vacuum System

6
  1. Place the heater-A/C control in the VENT position.
  2. Place the blower control in the LOW position.
  3. Place the temperature control(s) in the hot position.

The following conditions will cause sounds:

    • The air temperature valve motor(s) rotate the air temperature valve.
    • Warm air flows from all of the panel outlets.

7

Place the temperature control(s) in the cold position.

The following conditions will cause sounds:

    • The cold air flows from all of the panel outlets.
    • The air temperature valve motor(s) cause the air temperature valve to rotate.