ON-VEHICLE INSPECTION
PROCEDURE
1. INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET
HINT:
This is a method where a manifold gauge set is used to help locate the problem.
(a) Read the manifold gauge pressure when the following conditions are met:
Test conditions:
(1) Normally functioning refrigeration system Gauge Reading
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(2) Moisture is present in the refrigeration system.
Symptom |
Probable Cause |
Diagnosis |
Corrective Action |
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During operation, pressure on low pressure side cycles between normal and vacuum |
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(3) Insufficient cooling
Symptom |
Probable Cause |
Diagnosis |
Corrective Action |
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Gas leaks from the refrigeration system |
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(4) Poor circulation of refrigerant
Symptom |
Probable Cause |
Diagnosis |
Corrective Action |
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Refrigerant flow is obstructed by dirt inside the pipes of the condenser core |
Receiver is clogged |
Replace condenser |
(5) Refrigerant does not circulate.
Symptom |
Probable Cause |
Diagnosis |
Corrective Action |
---|---|---|---|
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Refrigerant does not circulate |
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(6) Refrigerant is overcharged or cooling effectiveness of condenser is insufficient.
Symptom |
Probable Cause |
Diagnosis |
Corrective Action |
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(7) Air is present in the refrigeration system.
Symptom |
Probable Cause |
Diagnosis |
Corrective Action |
---|---|---|---|
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Air in system |
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(8) Expansion valve malfunction
Symptom |
Probable Cause |
Diagnosis |
Corrective Action |
---|---|---|---|
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Expansion valve may be stuck |
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Check expansion valve |
(9) Insufficient compressor compression
Symptom |
Probable Cause |
Diagnosis |
Corrective Action |
---|---|---|---|
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Internal leak in compressor |
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Replace compressor |
Gauge readings (Reference)
Precaution
PRECAUTION
1. PRECAUTION FOR DISCONNECTING THE BATTERY CABLE
NOTICE:
When disconnecting the cable from the negative (-) battery terminal, initialize
the following systems after the terminal is reconnected.
System Name
See Procedure
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Inspection
INSPECTION
PROCEDURE
1. INSPECT THERMOSTAT
HINT:
The valve opening temperature is inscribed on the thermostat.
(a) Immerse the thermostat in water, and then gradually heat the water.
(b) Check t ...
Air Outlet Damper Control Servo Motor Circuit (B1443/43)
DESCRIPTION
The air outlet control servo motor sends pulse signals to indicate the damper
position to the A/C amplifier. The A/C amplifier activates the motor (normal or
reverse) based on these signals to move the mode damper to any position, which contro ...