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HVAC
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Step
Inspection
Action
14
Verify whether malfunction is in expan-
sion valve, air mix and compressor 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 com-
pressor 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 com-
pressor oil amount or a/c compressor
after compressor oil is replenished each
10 ml, Does high-pressure value in-
crease?
Yes
Troubleshooting completed.
(Explain to cus-
tomer that cause was insufficient compressor
oil.)
No
Replace A/C compressor.
(Cause is defective
AC compressor)
17
Verify whether malfunction is in expan-
sion 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 securely
and properly Are heater unit’s air mix
links, air mix cranks and air mix rods se-
curely and properly installed?
Yes Go to next step
No
Repair or install links, cranks and rods se-
curely in proper position.
19
Verify that expansion valve heat-sensing
tube within cooling unit is positioned se-
curely and correctly Is expansion valve
heat-sensing tube within cooling unit se-
curely installed in proper position?
Yes
Replace expansion valve, then go to next
step.
(Since valve opens too much, replace-
ment is necessary.)
No
Install heat-sensing tube securely in proper
position, 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.