GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1998 🢒 Regal 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 HVAC Air Delivery System Check
Table 1: Single Zone System Check (RPO C60)
Table 2: Dual Zone System Check (RPO CJ3)

Single Zone System Check (RPO C60)

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Start the engine.
  2. Set the heater-A/C control mode to MAX.
  3. Set the blower motor speed to 3 (medium).
  4. Set the temperature control to maximum cold.
    • Air conditioned inside air (recirculated) flows through the instrument panel outlets.
    • The A/C indicator lamp turns on.
    • The A/C compressor clutch is enabled.

2

Set the heater-A/C control mode to upper air distribution (instrument panel vents).
    • Air conditioned outside air flows through the instrument panel outlets.
    • The A/C indicator lamp remains on.
    • The A/C compressor clutch is enabled.

Instrument Panel Outlets Inoperative .

3

Press the A/C button.
    • Outside fresh air flows through the instrument panel outlets, without air conditioning.
    • The A/C indicator lamp turns off.
    • The A/C compressor clutch is disabled.

Air Recirculation Always On .

4

Set the heater-A/C control mode to bi-level air distribution (instrument panel and floor vents).
    • Outside air flows through the instrument panel and floor outlets, without air conditioning.
    • The A/C compressor clutch remains disabled.

Air Recirculation Inoperative .

5
    • Set the heater-A/C control mode to floor air distribution.
    • Set the temperature control to maximum heat.

Heated outside air flows through the floor and side window defogger outlets.
    •  Heated Air Inoperative .

6

Set the heater-A/C control to defog mode (windshield and floor vents).
    • Heated and dehumidified outside air flows through the windshield, side window defogger and floor outlets.
    • The A/C indicator lamp turns on.
    • The A/C compressor clutch is enabled.

Defrost Air Inoperative .

7

Set the heater-A/C control to defrost mode (windshield vent).
    • Heated and dehumidified outside air flows through the windshield outlet.
    • The A/C indicator lamp turns on.
    • The A/C compressor clutch is enabled.

Defrost Air Inoperative .

Dual Zone System Check (RPO CJ3)

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Start the engine.
  2. Set the heater-A/C control mode to MAX.
  3. Set the blower motor speed to medium (m3).
  4. Set the main temperature control to maximum cool.
  5. Set the passenger temperature control to maximum cool.
    • Air conditioned inside air (recirculated) flows through the instrument panel outlets.
    • The A/C compressor clutch is enabled.

2

Set the heater-A/C control mode to NORM.
    • Air conditioned outside air flows through the instrument panel outlets.
    • The A/C compressor clutch is enabled.

Air Recirculation Always On .

3

Set the heater-A/C control mode to BI-LEVEL.
    • Air conditioned outside air flows through the instrument panel and floor outlets.
    • The A/C compressor clutch is enabled.

Instrument Panel Outlets Inoperative .

4

Set the heater-A/C control mode to VENT.
    • Outside fresh air flows through the instrument panel outlets, without air conditioning.
    • The A/C compressor clutch is disabled.

Air Recirculation Always On .

5
  1. Set the heater-A/C control mode to HTR.
  2. Set the temperature control to maximum heat.

Heated outside air flows through the floor and side window defogger outlets.
    •  Heated Air Inoperative .

6

Set the heater-A/C control to Defrost.
    • Heated and dehumidified outside air flows through the windshield outlet.
    • The A/C compressor clutch is enabled.

Defrost Air Inoperative .

7
  1. Set the heater-A/C control mode to MAX.
  2. Set the main temperature control in the center position, between COOL and WARM.
  3. Set the passenger temperature control to maximum cool.
    • Air conditioned inside air (recirculated) flows through the instrument panel outlets.
    • The A/C compressor clutch is enabled.
    • The air flowing through the driver side vents is warmer than the air flowing through the passenger side vents.

8
  1. Set the heater-A/C control mode to HTR.
  2. Leave the main temperature control in the center position, between COOL and WARM.
  3. Set the passenger temperature control to maximum warm.
    • Heated outside air flows through the floor and side window defogger outlets.
    • The A/C compressor clutch is disabled.
    • The air flowing through the driver side floor vents is cooler than the air flowing through the passenger side floor vents.
    •  Heated Air Inoperative .