Table 4-2. Troubleshooting - TM-5-4120-369-140040

TM 5-4120-369-14

Troubleshooting - Continued

Table 4-2.

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

AIR CONDITIONER FAILS TO OPERATE - Continued

Step 4.

Check to see if mode selector rotary switch is improperly positioned or

is defective.

Turn selector to COOL or VENT.

Replace switch if defective

(paragraph 4-26).

Step 5.

Check to see if control circuit breaker or compressor circuit breaker is

in OFF position or is defective.

Reset circuit breaker(s) or replace defective circuit breaker (paragraph 4-26).

Step 6.

Check to see if high pressure or low pressure switch has cutout.

Reset high pressure or low pressure cutout. Note that time delay

relay starts compressor 30 seconds after reset.

Test control circuit transformer and rectifier for faulty

Step 7.

operation.

Replace defective transformer and/or rectifier (paragraph 4-28 and 4-29).

INSUFFICIENT COOLING

Check to see if the mode selector switch is improperly positioned.

Step 1.

Set switch to COOL.

Step 2.

Check to see if temperature selector control is inproperly positioned or

is defective.

Adjust setting or replace switch (paragraph 4-26).

Step 3.

Check to see if fresh air damper control is incorrectly set or

improperly adjusted.

Verify setting and, if neceesary, correct adjustment of damper

control (paragraph 4-39).

Step 4.

Check to see if evaporator outlet louver is bent or stuck in closed position.

Repair or replace louver. (paragraph 4-7)

Step 5.

Inspect condenser coil for dirt accumulation.

Clean coil (paragraph 4-5).

Step 6.

Inspect evaporator return air filter for dirt accumulation.

Clean filter (paragraph 4-3).

Step 7.

Check to see if evaporator fan is loose or defective.

Tighten if loose or replace if defective (paragraph 4-21).

4-5