TM 9-4120-402-14
Table 4-3. UNIT TROUBLESHOOTING - continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. AIR CONDITIONER DOES NOT START IN ANY MODE. - continued
Step 5. Check operation of the circuit breaker. (See paragraph 4-43.)
Replace circuit breaker if defective.
Step 6. Check operation of control power transformer. (See paragraph 4-39.)
Replace transformer if defective.
Step 7. Check operation of EMI filter and dc rectifiers assemblies. (See paragraph 4-38 and 4-42.)
Replace filter or rectifier if defective.
Step 8. Check for loose or damaged electrical connectors or damaged wires in wiring harnesses. (See
Tighten or replace connectors, or repair damaged wires.
Step 9. Check operation of the MODE selector rotary switch. (See paragraph 4-30.)
Replace switch if defective.
Step 10. Check that HIGH and LOW PRESSURE CUTOUT switches are not tripped.
PUSH TO RESET switch. If unit does not start, notify supervisor.
Step 11. Check logic box and motor controller assemblies. (See paragraph 36 and 4-37.)
Replace logic box or motor controller assembly if defective.
4-39
