GMC Chevrolet Camaro 1998 Service Manual page 146

1. .. 36 HV AC System - Manual HVAC
Improper Air Delivery Diagnosis (cont'd)
Step
.
Action
Value(s) Yes No
1. Apply vacuum to the vacuum line that leads to the
mode selector valve.
3
-
.2. Inspect each setting (MAX A/C to DEFROST).
. Does vacuum hold in every setting?
Go to Step 4 Go to Step 8
1.
Disconnect the vacuum line multi-connector under the
right side sourid insulator.
2. Turn the ignition switch to the RUN position (engine
not .running).
4
3. Select the HIGH blower motor assembly speed.
4.
Apply vacuum to each vacuum line individually
(except for the black and orange lines).
5. Inspect the lines for air flow at the proper outlets.
Refer to the Diagnostic Aid Chart.
Does air flow at the correct outlets?
Repair or replace the actuator linkage and/or air
5
valve {door).
.
.,
Is the repair complete
,,
Apply vacuum to the orange vacuum line.
6
Does the blower motor air flow noise increase?
Repair or replace the air inlet vacuum actuator linkage
7
and/or air inlet valve.
Is the repair complete?
1. Disconnect the vacuum line multi-connector at the
mode selector valve.
8
2. Apply vacuum to each line at the multi-connector that
is controlled by the- mode selector valve at a setting
where vacuum did not hold.
Is a vacuum leak present at one or more lines?
Repair or replace the vacuum line and/or the vacuum
9
actuator.
Is th.e repair complete?
10
Replace the mode selector valve.
Is the replacement complete?
Noise Diagnosis
Compressor related noise is usually caused by the
system. The compressor does not always
cause the noise.
-
Go to Step 6 Go to Step 5
"'
- -
System OK
-
System OK Go to Step 7
-
-
..
System OK
-
Go to Step 9 Go to Step 10
-
-
System OK
-
-
System OK
• Contact between the lines or hoses and the other · .
components
• The brackets are loose
• Other drive components
Fe.el the following items before you replace any of the
components. Many of the noises stop upon contact:
The following items may cause a moan noise:
• Thelines
• The hoses
• The brackets
The following types of noise may exist:
• Vibration and rattle
• Moan
• Screech
The following items may cause a vibration and
rattle noise:
• Misalignment of the belt in the groove
• The belt tensioner
• Incorrect refrigerant charge
• A loose or trin:;aligned bracket
• Contact between the lines 6r hoses and the other
components
• Other drive components
The following items may cause a screech noise:
• A worn serpentine belt
• The compressor bearings
• The compressor clutch
• The compressor alignment
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