GMC chervolet camaro 1999 Service Manual page 133

1-42 HVAC System - Manual
HVAC
Noise Diagnosis (cont'd)
Step Action
Value(s) Yes
No
1. Examine the blower impeller for the following
(
conditions:
• Wear spots
8
• Cracked blades
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• Cracked hub
• Improper alignment
2. Examine the blower case for wear spots.
Did you find any of these conditions? Go to Step 9
Go to Step 10
1. Replace the blower impeller.
9
2. Inspect the system again.
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Was the condition corrected? System OK
1. Replace the blower motor.
10
2. Replace the blower impeller.
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3. Reinspect the system.
Is the repair complete? System OK
Go to Step 11
11
Reinstall the original blower motor.
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-
Is the repair complete?
Go to Step 12
1. Select the HIGH blower motor speed.
12
2. Inspect for noise at each temperature selection
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(including the defroster operation).
Is there noise in all modes? Go to Step 13
Go to Step 17
13
Listen for noise in each temperature setting.
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Is there noise at all temperature settings? Go to Step 14
Go to Step 15
1. Inspect the system for obstructions or materials
between the blower impeller and the
14
temperature valve.
2. Repair or replace as the components as necessary.
-
-
3. Inspect the system again.
Is the repair complete?
System OK
Listen for noise in the blower motor.
15
Is there noise in all modes but not all temperature
- -
settings?
Go to Step 16
1. Inspect the temperature valve seals.
16
2. Repair or replace the valve seals as necessary.
- -
3. Reinspect the valve seals.
Is the repair complete?
System OK
17
Listen for noise in the blower motor.
-
Go to Step 18 Is there noise only in the DEFROST or HEATER mode?
Go to Step 19
1. Inspect the ducts for obstructions or materials.
2. Remove any materials or obstructions.
18
3. Inspect the DEFROSTER valve function.
- -
4. Repair or replace the valve as necessary.
5. Inspect the system again.
Is there noise in the blower motor?
System OK
19
Listen for noise in the blower motor.
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Go to Step20
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Is there noise only in the VENT or A/C mode?
1. Inspect the ducts for obstructions or materials.
2. Remove any materials or obstructions.
20
3. Inspect the DEFROSTER valve seals.
-
-
4. Repair or replace the seals as necessary.
5. Inspect the system again.
(
Is there noise in the blower motor? System OK