Section V: ORGANIZATIONAL TROUBLESHOOTING

TM 5-4120-341-13

ORGANIZATIONAL TROUBLESHOOTING

Section V.

4-15. GENERAL

a. This section provides information useful in diagnosing and correcting unsatisfactory operation or

failure of the air conditioner. Each malfunction is followed by a list of probabIe causes and actions to take

to remedy the malfunction. You should perform the tests/inspections and corrective actions in the order

listed.

b. This manual cannot list all malfunctions that may occur; nor all tests or inspections and corrective

actions. If a malfunction is not listed or is not corrected by Iisted corrective actions, notify your supervisor.

4-16. ORGANIZATIONAL TROUBLESHOOTING TABLE

Malfunction

Test or Inspection

Corrective Action

AIR CONDITIONER

1. AIR CONDITIONER FAILS TO OPERATE

Step 1.

Check to see if main power cord is plugged in.

Connect power cable to receptacle supplying 115 VAC, single phase, 60 Hz power.

Step 2.

Check to see if power receptacle connector iS defective.

Replace defective power receptacle connector (para. 4-29).

Step 3.

Check for Ioose electrical connections.

Tighten electrical connections.

Step 4.

Inspect for defective wiring.

Replace defective wiring. Use identical type wire, consult Appendix F, and solder all

terminal connections (para. 4-29).

Step 5.

Check the selector switch.

Observe position of the switch. Be sure switch is NOT in the OFF position.

Rotate the switch through all operating positions. If the air conditioner will

operate in some but not alI operating positions, check for a defective switch using

a multimeter.

Replace defective switch (para. 4-23).

2. INSUFFICIENT COOLING

Inspect sight glass for proper amount of refrigerant (para. 4-34).

Step 1.

Report condition to direct support maintenance personnel.

Step 2.

Check for dirty air filter.

Clean or replace air filter (para. 4-19).

Inspect evaporator coil for cleanliness.

Step 3.

Clean evaporator coil (para. 4-32).

Step 4.

Check compressor for proper operation (para. 4-30).

Report condition to direct support maintenance personnel.

Inspect for closed, bent or stuck louvers in the return air grill.

Step 5.

Open louvers, straighten bent louvers or replace damaged return air grill (para 4-18).

Step 6.

Check to see that circulating fan is securely mounted on motor shaft and that there is no

indication of damage to circulating fan.

Tighten setscrews in hub of circulating fan or replace damaged circulating fan (para 4-22).

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