AIR CONDITIONING SYSTEM TROUBLESHOOTING

TM 9-2320-303-24-2

AIR CONDITIONING SYSTEM TROUBLESHOOTING AND TESTING - CONTINUED

0227 00

AIR CONDITIONING SYSTEM TROUBLESHOOTING

Table 1. Problem - Warm Airflow When Air Conditioning Is On.

Possible Cause

Remedy

There is no refrigerant charge in system. Repair any leaks, evacuate system and add a full charge of refrigerant (WP 0297

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 0297 00), evacuate

system, and add a full charge of refrigerant (WP 0297 00).

Table 2. Problem - Low Evaporator Coil Outlet Pressure (Low Compressor Suction Pressure).

Possible Cause

Remedy

The expansion valve is not working

Replace expansion valve (WP 0299 00).

There are restrictions in line to expansion Remove line restrictions.

valve.

There is an insufficient refrigerant charge Locate leak. Recover refrigerant charge (WP 0297 00) and add a full refrigerant

in system.

Table 3. Problem - High Compressor Discharge Pressure.

Possible Cause

Remedy

There is an internal restriction in Replace condenser (WP 0304 00).

condenser. (Ice buildup on the condenser

or a cool spot on the line from the

condenser to the receiver-dryer).

Air is present in system.

Repair any leaks, evacuate system and add a full charge of refrigerant (WP 0297

Restriction in compressor discharge line. Repair or replace line (WP 0305 00).

Table 4. Problem - Evaporator Outlet Air Temperature Increases

as Compressor Discharge Pressure Drops.

Possible Cause

Remedy

The expansion valve setting is too low.

Replace expansion valve (WP 0299 00). Add a full charge of refrigerant (WP 0297