TM9-4120-370-14
TO35E9-229-1
TABLE 4-2. TROUBLESHOOTING (cont.)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
11. REDUCED HEATING CAPACITY.
Step 1. Check airflow out of conditioned air (evaporator) discharge grille. If air flow volume is low:
a. Adjust conditioned air (evaporator) intake grille louvers.
b. Clean and service, or replace, conditioned air filter element. (See para 4-32.)
c. Clean and service, or replace, mist eliminator. (See para 433.)
d. Clean evaporator coil, and entire evaporator section. (See para 468.)
Step 2. Check adjustment of fresh air damper and/or CBR filter, if installed.
Adjust properly.
Step 3. Check operation of heater thermostat (S3).
Disconnect input power before performing internal electrical troubleshooting.
Voltages used can be deadly.
Test thermostat. (See para 4-61.) Replace thermostat if defective.
Step 4. Check operation of individual heater elements (HR1, 2,3,4,5, and 6).
Test each element. (See para 462,) Replace defective elements,
Step 5. Check operation of Temperature control thermostat (S1).
a. inspect sensing bulb and capillary for damage or leakage. Replace entire control if bulb is damaged
or leaking.
b. Test Temperature control thermostat. (See para 439.) Replace entire control if defective.
12 REDUCED COOLING CAPACITY.
Step 1. Check condition of refrigerant displayed in sight glass.
a . If indicator (bull's eye) color is yellow or a light hue of chartreuse, or if numerous bubbles appear,
turn air conditioner OFF, and contact direct support maintenance for refrigeration system servicing.
b. If indicator (bull's eye) color is. green or a dark hue of chartreuse, or if refrigerant has a milky ap-
pearance, or more than an occasional bubble appears, thoroughly clean the condenser intake
screen, condenser fan guard, condenser coil, and entire condenser section to remove all obstruc-
tions.
4-42
