Section IV. ORGANIZATIONAL TROUBLESHOOTING

TM 5-4120-374-13

Section IV. ORGANIZATIONAL TROUBLESHOOTING

4-15. GENERAL

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

ure of the air conditioner. Each malfunction is followed by a list of probable 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 listed 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.

Disconnect input power source before performing Step 2.

Step 2. Check to see if power receptacle connector is defective.

Replace defective power receptacle connector (para. 4-28).

Disconnect input power source before internal electrical troubleshooting.

Step 3. Check for loose 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. 4-28).

Step 5. Check the selector switch.

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

b. Rotate the switch through all operating positions. If the air conditioner will operate in some,

but not all, operating positions, check for a defective switch using a multi meter.

Replace defective switch (para. 4-22).

2. INSUFFICIENT COOLING

Step 1. Inspect sight glass for proper amount of refrigerant (para. 4-33).

Report condition to direct support maintenance personnel.

Step 2. Check for dirty air filter.

Clean or replace air filter (para. 4-18).

Step 3. Inspect evaporator coil for cleanliness.

Clean evaporator coil (para. 4-31).