TM 9-4120-357-14
TABLE 4-2. TROUBLESHOOTING (Cont)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 6. With front access panel and junction box cover off, tag wires at K9 for identification and
disconnect. Apply 24-28 volts dc to terminals X1 and X2 of relay K9, and check continuity of
pairs A1-A2, B1-B2 and C1-C2. Each pair should indicate continuity.
Replace faulty relay.
Step 7. With front panel and junction box cover off, tag wires to time delay relay, K6, for identification and
disconnect. Apply 28 volts, dc, to primary terminals: positive (+) to terminal 1, and negative (-) to
terminal 5. Check continuity across secondary terminals to see that contact is made within 25+ 6
seconds of energizing.
Replace bad time delay relay.
WARNING
Hearing protection must be worn when maintenance is performed while air condi-
tioner is in operation. Failure to heed this warning can result in hearing loss or in-
jury.
Step 1. Check condenser intake screen for obstructions.
Clean screen or remove obstructions.
NOTE
Make sure that deflector door is fully open.
Step 2. Check condenser coil for dirt or obstruction.
Clean coil with vacuum cleaner, or remove obstruction.
Step 3. Visually, check to be sure that condenser fan is operating properly.
Tighten setscrews on loose impeller. Replace bad motor.
WARNING
Hearing protection must be worn when maintenance is performed while air condi-
tioner is in operation. Failure to heed this warning can result in hearing loss or in-
jury.
Step 1. Inspect filters for dirt and clogging
Clean and replace filters.
Step 2. Inspect mist eliminator for dirt and clogging.
Clean and replace mist eliminator.
Step 3. Check evaporator blower impellers for looseness, binding or damage.
Tighten setscrews or relieve binding as necessary, or replace damaged impeller(s).
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