TM 9-4120-357-14
TABLE 4-2. TROUBLESHOOTING (Cont)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Replace bad fuses.
Step 4. Remove front access panel, junction box cover, and control panel. Tag wires to mode selector
switch for identification, and disconnect wires from switch. Using an ohmmeter or continuity
tester, check continuity in each position in accordance with switch-position tabulation on wiring
diagram.
Replace faulty mode selector switch.
Step 5. Remove front access panel and junction box cover, and expose relay, K7, controlling condenser
fan motor. Tag wires for identification, and disconnect from relay. Apply 24-28 volts dc to
terminals X1 and X2, and check continuity of terminal pairs A1-A2, B1-B2 and C1-C2, using an
ohmmeter or continuity tester.
Replace bad relay.
connector P2, terminals A, B and C. If continuity is not shown in one or more leads, check from
relay (K7) wire Al, B1, C1 to connector J4, terminals E, G and J. If continuity is shown in all
three leads, check continuity from connector P2, terminals A, B and C to connector P4, terminals
E, G and J. If continuity is shown in all three leads, motor is bad.
Replace open wire leads, or replace motor.
Step 1. Make sure that power cable is properly connected.
WARNING
Disconnect power from the air conditioner before doing maintenance work on the
electrical system. The voltage used can be lethal.
Step 2. Check circuit breaker by pulling then pushing reset knob.
Replace bad circuit breaker.
Replace bad fuses.
Step 4. Remove front access panel, junction box cover and control panel. Tag wires to mode selector
switch for identification, and disconnect wires from switch. Using an ohmmeter or continuity
tester, check continuity in each position in accordance with switch-position tabulation on wiring
diagram.
Replace faulty mode selector switch.
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