TM 9-4120-399-14
Table 5-1. Direct Support Troubleshooting.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
3.
SUCTION PRESSURE TOO HIGH.
Step 1. Check for dirty air conditioner filter.
Clean filter.
Step 2. Check to see if conditioned discharge air guard and intake return air guard
louvers are closed.
Adjust louvers.
Step 3. Check for dirty evaporator coil.
Clean evaporator coil.
Step 4. Check sight glass for low refrigerant charge.
Step 5. Check to see if solenoid valve is stuck closed.
Replace valve if defective per para, 5-19
Step 6. Check operation of evaporator fan motor.
Replace motor if defective per para, 4-32
Step 7. Check to see if evaporator impeller fans are loose on shafts.
Tighten evaporator impeller fans on shafts per para. 4-30.
Step 8. Test the liquid quench expansion valve.
Step 9. Check distributor and evaporator coil tubing for kinks and restrictions.
5-3