General Maintenance Procedures

TM 5-4120-356-14

T a b l e 4-1. Troubleshooting (continued)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

FANS DO NOT OPERATE (continued)

Step 3.

I n s p e c t and test fan speed switch in accordance with paragraph

R e p l a c e damaged or defective fan speed switch.

Step 4.

I n s p e c t and test fan motor relays in accordance with paragraph

Replace damaged or defective relay(s).

11. UNIT DOES NOT OPERATE IN HEATING MODE

Step 1.

Continuity check heater circuit (see figure 3-28).

Repair or replace damaged or defective wiring.

Step 2.

I n s p e c t and test heater thermostatic switch in accordance with

Replace damaged or defective heater thermostatic switch.

Step 3.

Inspect and test selector switch in accordance with paragraph

Replace damaged or defective selector switch.

S e c t i o n III. Maintenance Procedures

a . R e m o v i n g and Installing

Panels and Grilles

D i r e c t Support Maintenance

o f the air conditioner components

normally requires the removal of panels and grilles

of the unit, and installation of these panels and

to provide access to the interior

a c c o m p l i s h e d . R e f e r to paragraph 3-9 for re-

grilles after maintenance has been

quired removal and installation of

panels and grilles during accomplishment of

Direct Support Maintenance.

S o l d e r i n g a n d Brazing.

(1) Use a silver solder on all soldered connections. Silver solder with

a 50 percent silver capacity and a melting point of approximately 1300 O F ( 7 0 4O C ) is

recommended.

4-7