119
No.
Pressure
Description
Analysis
Remedy
5
The high pressure is higher
than the normal value and
the low pressure is nearly
to zero or negative value
and the gauge swing
seriously
The air sent to the bus
sometime cold and
sometimes warm and the
inspection glass looks
yellow
Too much water
in the system desiccators
reaching the saturation
the frosting water blocked
the expanding valve
Change the desiccators
and make the vacuum
repeatedly and then
re-fill the refrigerant
6
The low pressure is much
higher than the normal
value and the high pressure
is a little bit higher than the
normal value
Cold is in sufficient
The condenser blower
doesn’t work normally or
there is blockage in the
condenser radiator
Check the electric
circuit diagram or
cleaning the condenser
7
The high are low and low
pressure are higher than
the normal values
The cold air is insufficient
Compressor interior
failure
Repair or change the
compressor
8
The high and low pressure
are lower than the normal
value
Evaporator wind flow is
insufficient
Evaporator blower not
running or low in
efficiently or the radiator
of the evaporator blocked
Check the electric
circuit diagram or clean
the evaporator radiator
9. Electric system trouble and remedy
Fault symptom
Possible cause
Eliminating method
the power lamp on the
control panel not light
1. + no power supply;
2. D+ not connected well;
3. harness not tight;
4. control unit failure;
1. generator D+ no output, exchange the
generator and repair
2. reconnect the cable D+;
3. reconnect the harness;
4. change the control panel or repair;
malfunction light on the
control panel light up
1. system pressure error;
2. pressure switch defective;
3. pressure switch harness not connected
well;
4. harness connection not well;
5. control panel failure;
1. to connect the manifold gauge and
eliminate the malfunction;
2. change the pressure switch and repair;
3. reconnect the pressure switch;
4. harness connection;
5. change the control panel or repair;
refrigerant lamp is not
lighted up
1. defrost sensor failure or connection
problem;
2. temperature control sensor failure or
connection problem;
3. temperature control sensor installation
position not good ;
4. temperature control switch defective;
5. harness connection not reliable;
6. Control panel defective
1. change the defrost sensor or connect
the cable again;
2. change the temperature control or
connect the harness again;
3. re-install the temperature control into
the correct position;
4. change the temperature control switch
or repair;
5. harness connection again;
6. change the control panel or repair;
condenser fan not
1. malfunction lamp light up;
1. check the problem according to the
