TM 9-4120-408-14
Table 4-4. Unit Troubleshooting Table. (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
7. Condensate Drain Warning Light on Control Module is Lit. (Continued)
b. Notify direct support maintenance.
8. Evaporator Fan Assembly Does Not Operate.
Step 1. Test mode selector switch (S1) (paragraph 4-21).
Replace defective mode selector switch (S1) (paragraph 4-21).
Step 2. Test 50 amp relay (K3) (paragraph 4-18).
a. Replace defective 50 amp relay (paragraph 4-18).
b. Notify direct support maintenance.
9. Condenser Vane Axial Fans Do Not Operate.
Test 50 amp relays (K1 and K2) (paragraph 4-18).
a. Replace defective or damaged 50 amp relays (paragraph 4-18).
b. Notify direct support maintenance.
10. Condenser Vane Axial Fans Both Run. but Compressor Does Not Start.
Step 1. Test thermostat (paragraph 4-23).
Replace defective thermostat (paragraph 4-23).
Step 2. Check to see if high pressure cut out switch has tripped.
a. Remove upper access panel (paragraph 4-10) and reset high pressure cut out switch.
b. If high pressure cut out switch continues to trip, check for restrictions in refrigerant line.
c. Check for obstructions to condenser air flow.
Step 3. Check to see if mode selector switch (S1) is in HIGH COOL position.
a. Position mode selector switch (S1) to HIGH COOL.
b. Notify direct support maintenance.
11. Compressor Starts Normally, but High Pressure Cut Out Switch Soon Trips.
Step 1. Check to be sure there is no restriction to air flow through condenser assembly.
Clean all obstructions from condenser inlet and outlet.
Step 2. Inspect refrigerant lines for damage or kinks which could cause a restriction in refrigerant flow.
Remove restrictions from refrigerant lines.
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