TM 9-2320-302-34
0009 00-7
AIR CONDITIONING SYSTEM TROUBLESHOOTING AND TESTING - CONTINUED
0009 00
AIR CONDITIONING SYSTEM TROUBLESHOOTING
Table 1. Problem - Warm Airflow When Air Conditioning Is On.
Table 2. Problem - Low Evaporator Coil Outlet Pressure (Low Compressor Suction Pressure).
Table 3. Problem - High Compressor Discharge Pressure.
Table 4. Problem - Evaporator Outlet Air Temperature Increases
as Compressor Discharge Pressure Drops.
POSSIBLE CAUSE
REMEDY
There is no refrigerant charge in system.
Repair any leaks, evacuate system (WP 0112 00), replace receiver-drier (WP 0118
00), and add a full charge of refrigerant.
Moisture in system.
If moisture is in system, ice crystals may form at expansion valve, blocking the
flow of refrigerant (off and on). Recover refrigerant charge (WP 0112 00), replace
receiver-drier (WP 0118 00), evacuate system, and add a full charge of refrigerant
(WP 0112 00).
POSSIBLE CAUSE
REMEDY
The expansion valve is not working
Replace expansion valve (WP 0114 00).
There are restrictions in line to expansion
valve.
Remove line restrictions.
There is an insufficient refrigerant charge
in system.
Locate leak. Recover refrigerant charge (WP 0112 00), replace receiver-drier (WP
0118 00), and add a full refrigerant charge (WP 0112 00).
POSSIBLE CAUSE
REMEDY
There
is
an
internal
restriction
in
condenser. (Ice buildup on the condenser
or a cool spot on the line from the
condenser to the receiver-drier).
Replace condenser (WP 0119 00).
Air is present in system.
Repair any leaks, evacuate system (WP 0112 00), replace receiver-drier
(WP 0118 00), and add a full charge of refrigerant (WP 0112 00).
Restriction in compressor discharge line.
Repair or replace line (WP 0121 00).
POSSIBLE CAUSE
REMEDY
The expansion valve setting is too low.
Replace expansion valve (WP 0114 00). Add a full charge of refrigerant
(WP 0112 00).
