TM 9-4120-404-14
3-37. LOGIC BOX ASSEMBLY (LGC). - Continued.
b. Test. - Continued
15. Reset mode switch S7. Do not place fault switches in the "OFF" position. Turn mode switch to "C" position.
No LED's shall illuminate. In 10 seconds, LED 3 shall illuminate.
16. Reset mode switch S7. Do not pl ace fault switches in the "OFF" position. Turn mode switch to "C" position.
Then immediately place S1, S4, S5, and S6 in the "OFF" position. In 10 seconds, LED's 2 and 7 shall
illuminate.
17. Place S2 in the "ON" position. LED's 2 and 7 remain illuminated. S2 has no effect.
18. Place S2 in the "OFF" position, and place S3 in the "ON" position. Then turn mode switch, S7, to "H"
position, with R6 set at the warmest position. After a 2-second delay, LED's 1 and 7 illuminate. S3 has no
effect.
19. Place all fault switches in the "OFF" position, and reset mode switch, S7. Turn mode switch to "V" position.
Then place S2 and S3 in the "ON" position. If LED 7 illuminated, it shall turn off. After a 10-second delay,
LED 3 shall illuminate. Turn mode switch, S7, to "C" position with R6 set to the coolest position. LED 2
shall not illuminate, LED 7 shall illuminate. After a 10-second delay LED 3 shall illuminate.
20. Place S2 and S3 in the "OFF" position, and reset mode switch, S7. Place S1 in the "ON" position, and turn
mode switch to "V" position. No LED's shall illuminate. After a 10-second delay, LED 3 shall illuminate.
c. Installation.
(1) Install logic box assembly (1) into unit and install four flat washers (4), four lock washers (3), and four
screws (2).
(2) Reconnect all wires and cables to logic box assembly (1). Remove tags.
(3) Install heater relay mounting hardware (see par. 3-31).
(5) Reconnect air conditioner to power source.
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