TM 9-4120-357-14
WARNING
Disconnect power from the air conditioner before performing maintenance work
on the electrical system. The voltage used can be lethal.
b. Testing. Disconnect the electrical connector from the housing of the solenoid valve, and apply a source of 24-28
volt dc power to the leads. A click should be heard if the valve is operating properly. If no click is heard, check continu-
ity of the coil with an ohmmeter or continuity tester. If no continuity is indicated, replace the coil; if continuity is indicated,
report the trouble to direct support maintenance for correction.
c. Coil replacement. Replace coils in the solenoid valves as directed in the following procedure: (See figure 4-13.)
(1) Disconnect wire leads from the connector receptacle.
(2) Remove the coil retaining nut from the top of coil housing.
(3) Lift the coil assembly straight up to remove it from the tube and plunger assembly.
(4) Place the new coil assembly over the tube and plunger assembly.
(5) Secure the data plate and housing assembly with the nut.
(6) Install the coil wire leads in connector, and tighten connector on housing.
(7) Connect the wiring harness plug to the receptacle.
d. Final assembly. Install the evaporator air intake grilles, and secure with 12 screws and washers in each grille.
Install front access panel by placing lower edge behind step in base plate. Push panel into position, and secure with four
panel fastener screws.
4-37. Sight-glass liquid indicator. (See figure 1-3.)
Visually inspect the sight-glass liquid indicator for obvious damage. Report condition to direct support maintenance if it is
damaged. Replace moisture indicator data plate if damaged.
4-38. Condenser Coil. (See figure 1-3.)
With the deflector door open, remove 12 screws from top and bottom edges of the condenser intake screen. Remove
screen, using a vacuum cleaner with brush attachment clean fins of condenser coil. If fins are bent or crushed,
straighten with a plastic or wooden blade such as a tongue depressor or equivalent. Replace intake screen, and secure
with 12 screws.
4-39. Evaporator Coil. (See figure 1-2.)
Service the evaporator coil in accordance with the following steps:
(1) Remove 16 screws and washers from the evaporator discharge grille, and remove the grille.
(2) Remove 31 screws from top and rear flange of the top panel, and remove the top panel or slide it back.
(3) Remove the mist eliminator by pulling it straight up.
WARNING
Compressed air used for cleaning purposes will not exceed 30 psi (2.1 kg/cm2).
Do not direct compressed air against the skin. Use goggles or full face shield.
(4) Clean the fins of the evaporator coils with compressed air at 25-30 psi (1.75-2.1 Okg/cm2) or with a fine
spray of cool water.
(5) Check the fins for bending or crushing. Straighten them if necessary, using a plastic or wooden blade such
as a tongue depressor.
(6) Replace the mist eliminator by sliding it down into channels.
(7) Position the top panel on the unit. Secure it with 31 screws in top and rear flange.
(8) Position the evaporator discharge grille on the unit. Secure it with 16 screws and washers.
4-45
