Section VI: TROUBLESHOOTING - TM-5-4120-369-140039

TM 5-4120-369-14

TROUBLESHOOTING

Section VI.

GENERAL.

4-13.

This section contains troubleshooting instructions for the isolation of causes and common

troubles that may occur during operation, and also gives the possible remedies to correct the

trouble.

ORGANIZATIONAL TROUBLESHOOTING CHART.

4-14.

General. Troubleshooting procedures for organizational maintenance personnel are listed

in table 4-2. As shown in the table, troubleshooting begins by identifying the malfunction. Next,

suitable tests of inspections are made in step-by-step order. Finally, a corrective action is given.

Remedies beyond the scope of organizational maintenance must be given in paragraph (b) and (c)

which follow :

Control Circuit. The cause for the failure of the system to operate can be narrowed

to a specific portion of the system if the control component associated with the failure can be

isolated. It is the purpose of safety devices to open the circuit under certain overload or

fault conditions. If a safety device is open, additional check is required to determine if the

open is due to faulty safety device or if the safety device is performing its intended function,

and the fault is located else where in the system. To check the control circuit, proceed as

follows:

(1) Disconnect air conditioner from source of power.

(2) Using a series test lamp or ohmmeter, check the continuity through each control

in the affected circuit with the control in the closed position while being checked. Use the

system schematic and wiring diagram for point-to-point circuit tracing.

(3) Replace each defective part with a serviceable like item.

Safety Devices. When testing the control circuit and associated components, take into

account the normal state of the safety device. Determine (1) whether it is normal for the device

to be open under the existing conditions or (2) if the open condition indicates trouble else where

in the air conditioner.

Troubleshooting

Table 4-2.

NOTE

Before you use this table, be sure you have performed all applicable operating checks.

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

AIR CONDITIONER FAILS TO OPERATE

Step 1.

Check to see if main power cable is connected.

Connect cable to power source.

Check to see if main power receptacle is defective.

Step 2.

Replace defective connector. (Paragraph 4-16.)

Check for loose electrical connections.

Step 3.

Tighten loose connections.

4-4