TM 9-4120-360-14
Section VIII. SOLENOID VALVES
Two solenoid valves are used in the air conditioner, one to close/open the liquid refrigerant line from the condenser coil to
the evaporator coil expansion valve, the other to close/open the pressure equalization circuit from the discharge side of
the compressor to the suction side. Both valves are alike; however the liquid line solenoid valve is located above and
behind the filter-drier in the lower part of the unit, while the pressure equalizer solenoid valve is located in the upper rear
part of the air conditioner.
5.47. Acces
a. Gain access to the liquid line solenoid valve in accordance with the following instructions.
(1) Unscrew two panel fastener screws in the upper edge of the lower panel, and remove the panel.
(2) Unfasten six cam-lock studfasteners from thee evaporator air intake grille by turning them counterclock-
wise. Remove the grille. Remove two screws from the air filter retainer and remove the air filter.
WARNING
Disconnect power from the air conditioner before performing maintenance on the electrical system.
The voltage used can be lethal.
(3) Disconnect the wiring harness plug from the receptacle on the left end of the control panel assembly.
(4) Remove four screws from the corners of the control panel mounting flanges.
(5) Remove the screw
and 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.
(6) Loosen the set screw with in end of the core end fitting on the circuit breaker reset cable. Straighten the end
of the rest cable, and slide the core end fitting off the cable.
(7) Remove two screws and loop clamps attaching the circuit breaker reset cable to the junction box. Re-
move the cable from the hole in the actuator arm connector plate.
(8) Unscrew four panel mounting screws from the two end mounting flanges of the junction box.
(9) Lean the junction box outward, disconnect
the two wiring harness plugs from the receptacles on
the
back of the junction box. Remove the junction box from the air conditioner.
b. G a i n access to the pressure equalizer solenoid valve as directed in the following procedure:
(1) Remove 18 screws and washers from the four sides of the fabric cover, and remove the cover from the air
conditioner.
(2) Remove 15 Screws and packing washers from the top of the panel and five screws from the rear flange.
Remove the top panel.
5.48. Inspection/test
Inspect the solenoid valves visually for physical damage, loose connectors, loose coil and housing and broken or frayed
wires or missing insulation. Test operation by applying 24-28 volts to to the pins of the electrical connector, and listening
for a sharp click which indicates that the solenoid plunger is working properly. If damage is evident or solenoid plunger
fails to operate. replace the coil assembly. If valve still does not operate properly, as indicated by pressure testing or
troubleshooting, replace the diaphragm or the entire valve, as necessary.