TM 9-4120-408-14
Table 4-4. Unit Troubleeshooting Table
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
2. Air Conditioner Suddenly Stops. (Continued)
WARNING
Do not work on equipment with power connected. Electrocution hazard is present. Failure to obey this
warning may result in death or serious personal Injury.
Disconnect, clean connectors, and reconnect all connectors or connect power from a source supplying 28 vdc.
Step 3. Refer to wiring diagrams (Figure H-1, H-2, and H-3) and inspect/test wiring.
Repair or replace damaged or defective wiring as required.
3. Insufficient Cooling Capacity.
Step 1. Ensure that all doors, windows, and other openings in the shelter or enclosure are tightly closed.
Tightly close all openings.
Step 2. Ensure that the evaporator outlet is not blocked or obstructed.
Unblock or remove obstructions.
Step 3. Ensure that the condenser inlet and outlet are not obstructed.
Remove obstructions.
Step 4. Inspect for obstructions in fins of evaporator coil or damaged evaporator coil.
a. Remove obstructions and clean evaporator coil.
b. Notify direct support maintenance.
Step 5. Inspect thermostat temperature sensing bulb and capillary tube for damage and test thermostat
Step 6. Remove lower access panel (paragraph 4-10) and with unit operating in HIGH COOL mode, check
refrigerant condition in liquid/moisture indicator.
4-9