TM 9-4120-378-14
Table 4-2. Unit Troubleshooting - Continued
Malfunction
Test or Inspection
Corrective Action
2.
INSUFFICIENT COOLING - Continued
Inspect evaporator inlet air filter for dirt.
Step 4.
See whether Temperature Selector switch is set incorrectly or is defective.
Step 5.
Adjust setting or replace switch or other corrective action. (Refer to paragraph
Step 6.
Check evaporator outlet louver to see whether it is bent, or stuck in the CLOSED
position.
Repair or replace louver. (Refer to paragraph 4.11.)
Observe evaporator fan motor to see whether it is worn or defective.
Step 7.
Report fault to Direct Support Maintenance personnel or replace motor. (Refer to
Check to see whether evaporator impeller fan is loose or defective. Tighten
Step 8.
setscrew or replace impeller fan. (Refer to paragraph 4.32.)
3.
EVAPORATOR OR CONDENSER FAN MOTOR FAILS TO OPERATE
Make sure that power cable is properly connected.
Step 1.
Connect cable.
Check for bad fan motor. (Refer to paragraphs 4.33 and 4.36.) Check for bad start
Step 2.
capacitor by using an ohmmeter. (Refer to paragraph 4.29.)
Replace motor. (Refer to paragraphs 4.33 and 4.36.)
Step 3.
Check evaporator or condenser fan motor for binding.
Relieve binding or replace fan motor. (Refer to paragraphs 4.33 and 4.36.)
Step 4.
Check continuity of receptacle or plus terminals. (Refer to paragraphs 4.33 and
Replace terminals or receptacles. (Refer to paragraph 4.36.)
Step 5.
source, then check continuity of contacts that should be closed. (Refer to
Replace bad relay. (Refer to paragraph 4.25.)
4-16
