TM 9-4120-378-14
Table 4-2. Unit Troubleshooting - Continued
Malfunction
Test or Inspection
Corrective Action
4.
COMPRESSOR WILL NOT START - Continued
Check continuity across primary winding and across secondary winding of control
Step 5.
transformer to see whether windings are good. (Refer to paragraph 4.31.)
Replace bad transformer. (Refer to paragraph 4.31.)
Step 6.
Apply 30 volts AC across side input terminals; check for 24-28 volts DC across
output terminals (marked + and -) of rectifier. (Refer to paragraph 4.30.)
Replace bad rectifier. (Refer to paragraph 4.30.)
Step 7.
Observe operation of time delay relay and check continuity. (Refer to paragraph
Replace bad relay. (Refer to paragraph 4.25.)
5.
INSUFFICIENT HEATING
Step 1.
Check that Mode Selector switch is in HIGH HEAT position.
a. Switch to HIGH HEAT position.
b, Replace bad Mode Selector switch. (Refer to paragraph 4.24.)
Check that Evaporator Fan Toggle switch is in HIGH SPEED position.
Step 2.
a, Switch to HIGH SPEED position.
b. Replace bad Evaporator Fan Speed switch. (Refer to paragraph 4.24.)
Step 3.
Check that Temperature Selector switch is in WARMER position.
a. Switch to WARMER position.
b. Replace bad Temperature Selector switch, (Refer to paragraph 4.24.)
Step 4.
Check that the COMPRESSOR CIRCUIT BREAKER is in the ON position.
a. Switch to ON position.
b. Replace bad COMPRESSOR CIRCUIT BREAKER. (Refer to paragraph 4.24.)
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