TM9-4120-401-14
THERMISTOR (RT1).
This task covers:
a. Inspect
b. Test
c. Replace
INITIAL SETUP
Equipment Conditions:
Tools
Refrigeration Unit Service Tool Kit
Appendix B, item 1
Materials/Parts
Use disconnect switch (NOT POWER
CABLE) to disconnect power to unit.
Thermistor
Damage to cable connector pins will
result if cable is used.
Tiedown straps (6)
Disconnect power at power source.
Remove top panel (para 4-11).
a. Inspect.
Check thermistor (1) for loose lead wires and general condition. Replace if damaged.
b. Test.
(1) Remove connector (P3) (2) from logic box connector (J3).
(2) Using multimeter set to read resistance, check continuity between connector (P3) (2) terminals 1 and 2.
Resistance should be between 2.4 kiloohms and 33.2 kiloohms. Replace if defective.
c. Replace.
(1) Remove connector (P3) (2) from logic box connector (J3) (3).
(2) Tag and disconnect (P3) harness leads (4) from terminal board (TB3) (5). Remove wiring harness.
(3) Remove six tiedown straps (6).
(4) Remove screw (7), lock washer (8), flat washer (9), and clamp (10).
(5) Remove two sets of screws (11), lock nuts (12), and clamps (13).
(6) Carefully pull thermistor (1) from unit wiring harness.
(7) Remove thermistor (1) lead pins from connector (P3) (2).
(8) Remove pins from thermistor (1) leads and install on replacement thermistor leads.
(9) Insert thermistor (1) lead pins into connector (P3) (2).
(10) Secure wire leads with six tiedown straps (6).
4-86
