TM 9-4120-360-14
5.18. Access
Gain access to the compresor as directed in the following procedure:
WARNING
Disconnect power from the air conditioner before performing maintenance on the electrical system.
The voltage used can be lethal.
a. Unscrew two panel fastener screws in the upper edge of the lower panel and remove the panel.
b. Straighten the end of the circuit breaker reset cable, loosen the setscrew in the end of the cable end fitting, and
remove the end fitting.
c. Remove screws from two loop clamps securing the flexible cable to the junction box, and remove cable from
junction box and circuit breaker actuating arm connector plate.
d. Unscrew two panel fastener screws in the mounting flanges at each end of the junction box.
e. Disconnect wiring harness plug from receptacle on left end of control panel assembly, and remove four
screws from the corners of the contro lpanel mounting flanges. Reconnect the wiring harness plug to support the control
panel assembly.
f. Swing junction box out and disconnect wiring harness plugs from receptacles on near surface. Remove
junction box.
5.19. Inspection/Test
Inspect the compresso rfor damage and loose mounting bolts. If damage is evident, test for leaks, using an electronic leak
detector, or soap solution to detect bubbles. If mounting bolts are loose, tighten them. If leaks are detected in,@
compressor, discharge the refrigeration system and replace the compressor. If electrical trouble is indicated, check
continuity as follow:
a. Disconnect plug, P4, from the electrical junction box on the compressor.
b. Check continuity of the following pain of pins in receptacle J4: Compressor motor windings A-B, B-C and
A-C, and the normally closed thermal overload on pins D and E. Also check crankcase heater and thermostat on Pins F
and G. Continuity should exist. Continuity should not exist between compressor housing and pins A,B,C, and D. If
continuity requirements are not met for pins A,B, and C or pins D and E, replace the compressor. If continuity
requirements are not met for pins F and G, replace only the crankcase heater or thermostat as required.
5.20. Removal of Crankcase Heater
Remove the crankcase heater from the compressor as directed in the following steps:
a. Remove the retaining spring (7, figure 5-4) from the ends of the crankcase heating element(6).
b. Remove compressor junction box cover (4) and remove electrical receptacle (2) by removing four screws.
c. Unsolder wire lead from heating element at receptacle pin G and cut splice to heater thermostat lead.
d. Spring the ends of the heating element apart slightly so that the heating element can be maneuvered around
and over the top of the compressor housing to remove it.
5.21. Installation of Crankcase Heater
Install the crankcase heater as follows: