GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1998 🢒 Firefly (Canada) 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Air Delivery Improper

Step

Action

Value(s)

Yes

No

1
  1. Set the mode to VENT.
  2. Set the temperature to full COLD.
  3. Set the blower speed to OFF.
  4. Inspect for airflow at the following outlets:
    5. • The vent
    • The heater
    • The defroster
    • The side window defroster

Is there airflow coming out of any of the outlets?

--

Go to Step 7

Go to Step 2

2
  1. Set the blower speed to HI.
  2. Inspect for airflow at the following outlets:
    3. • The vent
    • The heater
    • The defroster
    • The side window defroster

Is air blowing through the vent outlets at ambient temperature and is no air blowing through the heater, the defroster, and the side window defroster outlets?

--

Go to Step 3

Go to Step 7

3
  1. Set the mode to HEAT.
  2. Set the temperature control to full HOT.
  3. Inspect for airflow at the following outlets:
    4. • The vent
    • The heater
    • The defroster
    • The side window defroster

Is hot air blowing through the heater outlet at the blower hi speed, is minimum hot air blowing through the defroster, and the side window defroster outlets, and is no air blowing through the vent outlets?

--

Go to Step 4

Go to Step 7

4
  1. Set the mode to DEFROST.
  2. Inspect for airflow at the following outlets:
    3. • The vent
    • The heater
    • The defroster
    • The side window defroster

Is hot air blowing through the defroster outlet at blower hi speed, is minimum hot air blowing through the heater and the side window defroster outlets, and is no air blowing through the vent outlets?

--

Go to Step  5

Go to Step 7

5
  1. Disconnect the affected control cable(s) at the door(s).
  2. Inspect the door travel and effort.

Is the door travel and effort OK?

--

Go to Step 6

Go to Step 8

6

Inspect the control cable(s) travel by moving the corresponding control at the heater control unit.

Is the control cable travel OK?

--

Go to Step 9

Go to Step 10

7

Repair the affected control cable(s) as necessary. Refer to the following:

Is the repair complete?

--

Go to Step 11

--

8

Repair the affected door at the heater case.

Is the repair complete?

--

Go to Step 11

--

9

Reinstall the control cable(s).

Is the repair complete?

--

Go to Step 11

--

10

Repair the control cable(s) attachment at the heater control unit.

Is the repair complete?

--

Go to Step 11

--

11

Perform the functional test. Refer to Function Test .

Is the repair complete?

--

Go to Heater Blower Controls System Check

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