TM 9-4120-385-14
Table 4-2. TROUBLESHOOTING FOR UNIT MAINTENANCE
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 7. Test electrical components.
Replace components as required.
Step 8. If air conditioner fails to start, refer to Paragraph 5-1.
2. EVAPORATOR/CONDENSER BLOWERS FAIL TO START
Step 1. Check that power supply is connected.
Connect power supply.
Step 2. Check that CIRCUIT BREAKER (CB) has been RESET.
RESET CIRCUIT BREAKER.
Step 3. Check motor bearings and fans by:
Disconnect power supply from air conditioner.
Rotate the blower wheels by hand to see if the bearings are frozen or if shaft is bent, or if
fans are loose or broken.
Replace defective motor.
Step 4. Move mode selector switch to each of the four positions: COOL, VENTILATE, LO HEAT, and HI HEAT. Move
mode selector switch to VENTILATE.
Test switch S. Replace switch if defective. Refer to Paragraph 418.
Step 4.1. Test K9 time delay relay. Refer to paragraph 4-20 Test.
Replace if defective. Refer to Figure 4-25.
Step 5. Test motor. Refer to Paragraph 5-10.
Repair or replace defective motor. Refer to Paragraphs 4-24 and 5-10.
WARNING
High voltage in air conditioner can kill.
Change 1 4-17
