GMC Chevrolet Camaro 1998 Service Manual page 141

HVAC
HVAC System - Manual 1-31
Heating Insufficient (cont'd)
Step Action Value{s) Yes
No
1. Adjust the heater controls to the following settings:
1.1. Hea,ter mode
1.2. High blower speed
2
1.3. Full warm
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2. Idle the vehicle.
3. Inspect the floor air outlet.
4.
Inspect the outlet attachment.
Is there high air flow? Go to Step 3 Go to Step 16
3
Inspect the blower speed for airflow change.
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Does the speed of th.e airflow change? System OK Go to Step 4
1. Inspect the blower switch and the resistor.
4
2. R~pair th~ blower switch and the resistor.
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3. Complete the heater output temperature check.
Is the heater output temperature correct? Go to Step 5 Go to Step 6
1. Inspect the vehicle for cold air leaks at the following
locations:
5
• The cowl
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• The heater case
• The vents
2. Inspect under the seat for obstructions. ·
1. Place the ignition switch in the RUN position.
2. Place the blower on LOW.
3. Rotate the temperature control knob to the mid
6
position.
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4. Rotate the knob rapidly to the full HOT position.
5. Listen for valve slam at the end of the control knob
rotation.
Is there a valve slam? Go to Step 9 Go to Step 7
1. Inspect the temperature control cable for correct
7
attachment at the control and the heater module.
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2. Repair as necessary.
Is there valve slam? Go to Step 9 Go to Step 8
Replace the temperature control cable. Refer to
8
Temperature Control Cable Replacement.
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Is the repair complete?
System OK
1. Place the temperature valve in full WARM.
2. Start the vehicle.
3. Ensure that the air temperature around the hoses is
9
at least 24°C (85°F).
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4.
Inspect the temperature of the heater inlet and outlet
hoses by feel.
Is the inlet hose hotter than the outlet hose? Go to Step 13 Go to Step 10
1. Back flush the heater core.
2. Drain and refill the coolant. Refer to Draining and
10
Filling Cooling System (V6) or Draining and Filling
Cooling System (VB) in Engine Cooling.
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3. Retest.
Is the inlet hose hotter than the outlet hose? Go to Step 11 Go to Step 12