TABLE 4-2. TROUBLESHOOTING - TM-5-4120-347-140057

TM5-4120-347-14

TABLE 4-2. TROUBLESHOOTING

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

1. AIR CONDITIONER WILL NOT START IN ANY MODE.

Step 1.

Check to see if the circuit breakers are tripped.

Reset circuit breakers.

Step 2.

Check to see if input power has been disconnected.

Connect input power.

Disconnect input power before performing internal electrical troubleshooting. Voltages

used can be lethal.

If input power has been disconnected for an unknown period of time, do not start in COOL

mode until it has been reconnected for a minimum of four hours.

Step 3.

Check for loose or damaged electrical connectors or damaged wires in wiring harnesses.

Tighten or replace connectors, or repair damaged wires.

Step 4.

Check that internal wiring at terminal boards TB3 and TB4 are wired for the connector to which

input power is connected.

See paragraph 4-6 and move wires if necessary.

Step 5.

Check for defective circuit breaker.

Replace circuit breaker if defective.

Step 6.

Check for defective mode selector switch.

Replace switch if defective.

2. CONDITIONED (EVAPORATOR) AIR FAN DOES NOT START OR STOP DURING OPERATION IN ANY

MODE.

Disconnect input power before performing internal electrical troubleshooting. Voltages

used can be lethal.

Step 1.

Check operation of evaporator fan motor.

Test motor. Contact direct support maintenance if motor is defective.

Step 2.

Check operation of mode selector switch.

Test switch. Replace switch if defective.

Step 3.

Check electrical connections and wiring.

Tighten or replace connectors, or repair or replace damaged wires.

Step 4.

Check fan for binding.

Relieve binding or replace fan.

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