TM 9-4120-402-14
Table 4-3. UNIT TROUBLESHOOTING - continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
6. REDUCED HEATING CAPACITY. - continued
Step 4. Check to be sure that excessive cold, outside air is not being introduced through the fresh air damper.
Fully close damper; then, if condition improvesadjust properly.
,
Step 5. Check air flow out of conditioned air (evaporator) discharge grille. If air flow volume is low:
(1)
Adjust conditioned air (evaporator) intake grille louvers.
(2)
Clean and service, or replace conditioned air filter element. (See paragraph 4-23.)
(3)
Clean and service, or replace mist eliminator. (See paragraph 4-25.)
(4)
Clean evaporator coil and entire evaporator section. (Seeapagraph 4-50.)
WARNING
Disconnect input power before performing internal electrical troubleshooting.
Voltages used can be deadly.
CAUTION
Use disconnect switch (NOT POWER CABLE) to disconnect power to unit.
Damage to cable connector pins will result if cable is used.
Step 6. Check for loose or damaged wires and terminals.
Tighten loose or damaged terminals. Repair or replace damaged wires. (See paragraph 4-26.)
Step 7. Check operation of heater cutout switch.
Test switch. (See paragraph 4-45.) Replace switch if defective.
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