1848 / 1906
HVAC
34
Step
Inspection
Action
sor oil to the A/C compressor.
Verify that the noise is no longer heard. Adjust
refrigerant to specified amounts.
14
Verify whether malfunction is in
expansion valve, air mix and com-
pressor oil or elsewhere does
refrigerant’s high-pressure value
hardly increases?
Yes
Go to next step.
(Pressure hardly increases.)
No
Go to step 17.
15
Verify whether a malfunction is in
compressor oil amount and a/c
compressor or elsewhere when
engine is racing, does high-
pressure value increase?
Yes
Return to step 3.
No
Go to next step.
16
Verify whether malfunctions is in
compressor oil amount or a/c com-
pressor after compressor oil is
replenished each 10 ml, does high-
pressure value increase?
Yes
Troubleshooting completed.
(Explain to customer
that cause was insufficient compressor oil.)
No
Replace A/C compressor.
(Cause is defective AC
compressor)
17
Verify whether malfunction is in
expansion valve or elsewhere is
only refrigerant low-pressure value
high?
Yes
Go to step 20.
No
Go to next step.
18
Verify that air mix is installed se-
curely and properly are heater
unit’s air mix links, air mix cranks
and air mix rods securely and
properly installed?
Yes
Go to next step.
No
Repair or install links, cranks and rods securely in
proper position.
19
Verify that expansion valve heat-
sensing tube within cooling unit is
positioned securely and correctly is
expansion valve heat-sensing tube
within cooling unit securely in-
stalled in proper position?
Yes
Replace expansion valve, then go to next step.
(Since valve opens too much, replacement is
necessary.)
No
Install heat-sensing tube securely in proper posi-
tion, then go to next step.
20
Verify that malfunction symptom
occurs after repair does cool air
blow out?
(Are results of refrigerant
system performance test okay?)
Yes
Troubleshooting completed.
Explain repairs to customer.
No
Recheck malfunction symptoms, then repeat from
step 1 if malfunction recurs.