TM 9-4120-360-14
WARNING
Use great care to avoid contact with liquid refrigerant or refrigerant gas being discharged under pres-
sure. Sudden and irreversible tissue damage can result from freezing. Wear thermal protective gloves
and a face protector or goggles in any situation where skin or eye-contact is possible.
Prevent contact of refrigerant gas with flame or hot surfaces. Heat causes the refrigerant to break
down and form carbonyl chloride (phosgene), a highly toxic and corrosive gas.
c. Unscrew the two panel fastener screws in the upper edge of the lower panel, and remove the panel.
d. Unfasten six cam-lock stud fasteners from the evaporator intake grille by turning them counterclockwise.
Remove the grille and the air filter.
e. Disconnect the wiring harness plug from the receptacle on the left end of the control panel assembly.
f. Remove four screws from the corners of the control panel mounting flanges
g. Remove the screw from the loop clamp holding the thermostat sensor bulb to the wall of the evaporator air
intake chamber. Withdraw the control panel assembly from the air conditioner while carefully leading the thermostat
sensor bulb and capillary tube through the grommet and hole in the floor of the intake chamber.
h. Loosen the setscrew in the end of the core end fitting on the circuit breaker reset cable. Straighten the end of
the cable. and slide off the core end fitting.
i. Remove two screws. and remove two loop clamps holding the circuit breaker reset cable to the junction box.
Remove the reset cable from the actuator arm connector plate.
j. Lean the junction box outward, and disconnect the two wiring harness plugs from the rear.
k. From connector plug, P3, which has been disconnected from the junction box, unsolder wires from pins O
and g. Release or cut wire ties, and separate wires from cable.
WARNING
Do not perform the following step until all refrigerant has been discharged from the system.
l. Using a wrench on each hex (presssure switch and tee fitting) remove the pressure switch.
5.33. Inspection/Test
Inspect the pressure switch for physical damage, cut or broken wires or missing insulation. Replace if damaged. Test the
pressure switch as directed in the following procedure:
a. Connect an ohmmeter, multimeter or other continuity testing device to the wire leads of the switch.
CAUTION
Do not use compressed air to pressurize the switch. Traces of oil, moisture and other contaminants
could be carried into the refrigeration system.
b. Connect a
cylinder of
dry nitrogen to
the body of
the pressure switch, and slowly pressurize the switch.
c. Observe the pressure gauge and the meter of the continuity tester. Continuity should be indicated when
pressure reaches 400 16 psi (28.12 1.13 kg/cm2).
d. Gradually reduce pressure to
the switch while observing the pressure gauge and the continuity tester.
Continuity should drop out at 350 16 psi (24.6 1.13 kg/cm2).
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