TM 9-4110-255-14
4-24. CONTROL RELAYS K1, K2 AND K3 TESTING AND REPLACEMENT.
This task covers:
a. Testing
b. Removal
c. Installation
INITIAL SETUP
Materials/Parts:
Equipment Conditions:
Lock Washers (2)
Refrigeration unit shut down (para 2-7) and battery
1, Appendix G
disconnected (para 4-35).
Lock Washer (2 Each Relay)
Control box cover door raised and latched.
5, Appendix G
Defrost timer removed (para 4-29).
Marker tags (6) (K1, K3)
4, Appendix E
Marker tags (4) (K2)
4, Appendix E
a. Testing. (See Figure 1-4.)
(1) Be sure battery has been disconnected then remove two bolts (1) and lock washers (2). Open control
panel (3). Discard lock washers.
(2) Tag and disconnect wire leads (4).
(3) Using multimeter set to measure continuity, check each control relay (5) coil continuity between terminals
A to B. Continuity should be indicated. If no continuity was indicated, replace control relay.
(4) Using multimeter set to measure continuity, check each control relay (5) contact continuity between
terminals 7 to 4 (K3 and K4) and 9 to 6 (K4). No continuity should be indicated. If continuity was
indicated, replace control relay (5).
(5) If no failure was indicated, using tags and wiring diagram (fig. 1-4), install wire leads (4). Remove tags.
(6) Close control panel (3) and install two new lock washers (2) and bolts (1).
b. Removal.
(1) Be sure battery has been disconnected and remove two bolts (1) and lock washers (2). Open control panel
(3). Discard lock washers.
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