TM 9-4120-404-14
3-44. COIL FROST SWITCH (S2). - Continued
b. Test.
(1) Using a multimeter, place probes on each of the two terminals of the coil frost switch.
(2) If no frost is present on evaporator coil, there should be continuity across terminals.
(3) If frost is present on evaporator coil, there should be an infinity reading across terminals.
(4) If coil frost switch fails either of the above tests, it must be replaced.
c. Installation.
(1) Install two nuts (4), two lock washers (3), two screws (2), and coil frost switch (t}.
CAUTION
Use care when removing capillary from evaporator coil. Damaging the capillary
tube of the coil frost switch will cause the unit to malfunction.
(2) Carefully position capillary tube (6) of coil frost switch (1) in an area close to the evaporator coil (5).
(3) Refer to wire tags installed during removal and reconnect all wires to the coil frost s itch (1) and then
w
remove tags.
(4) Install front cover (see para. 3-27).
(5) Reconnect air conditioner to power source.
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