AC DOES NOT COOL OR COOLS INADEQUATELY - Continued

DRAFT

TB 9-2320-279-13-1

AC DOES NOT COOL OR COOLS INADEQUATELY - Continued

WARNING

Moving engine components can cause severe injury. Keep away from fan, belts, and pulleys while

engine is running.

Wear protective goggles and nonleather gloves when servicing air conditioner system. Failure to

comply may result in injury to personnel.

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VISUAL INSPECTION

NOTE: AC condenser fan may not turn on in extremely

cold, or off in extremely hot ambient temperatures.

While assistant slowly adjusts temperature control

switch from its coldest position to off position, verify that

the on/off cycle for the AC condenser fan motor varies

as the temperature control switch is adjusted.

(a) If the AC condenser on/off cycle does not vary

when the temperature control switch is

adjusted, turn engine switch OFF

(TM 9-2320-279-10) and replace temperature

control switch (WP 0044). Verify repair, go to

Step 22 of this fault.

(b) If the AC condenser on/off cycle varies when

the temperature control switch is adjusted, go

to Step 9 of this fault.

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VISUAL INSPECTION

(1)

Turn temperature control switch to the coldest

position (fully clockwise) (WP 0004).

(2)

Inspect AC system operation. System output

should be 20F (-6.67C) cooler than ambient

temperature of cab.

(a) If AC system is not providing adequate cooling.

1. Shut off engine (TM 9-2320-279-10).

2. Perform leak test (WP 0049).

3. Recover R-134a refrigerant (WP 0050).

4. Repair leaks found.

5. Replace AC condenser dryer (WP 0025).

6. Evacuate and charge system with new

R-134a refrigerant (WP 0050).

7. Verify repair, go to Step 22 of this fault.

(b) If AC system is providing adequate cooling, go

to Step 22 of this fault.

HEMAC180