Section XIV: MAINTENANCE OF FAN MOTOR SWITCHES

TM 5-4120-352-14

(f) Refer to figure 4-2 and install evapo-

d. lnstallat ion.

rator air inlet louver.

(1) Evaporator Fan Motor. Install evapo-

e. Condenser Fan Motor. Assemble motor on

rator fan motor as follows:

mounting plate and install motor and mounting

(a) Set motor on fan-and-motor base with

plate as follows:

motor base in fan-and-motor shaft (fig. 4-11). In-

(1) Refer to figure 4-13 and install bushings

stall four cap screws and lockwashers through un-

(8) in mounting plate (9) if they were removed.

derside of base to secure motor. Tighten setscrew in

(2) Place a washer (7) over each bushing and

fan-and-motor shaft.

set motor (6) on washers. Install four screws (3),

(b) Install fan and motor assembly on re-

washers (5), and lockwashers (4). Install collar (2)

silient mounts and install four screws and lock-

on motor shaft and install setscrew (1).

washers (fig. 4- 11).

(3) Install plate and motor in air conditioner

(c) Install brackets above fan. Install tem-

and slide fan impeller (fig, 4-12) on motor shaft. In-

perature selector switch bulk in clamps and secure

stall four screws and flat washers.

clamps with screws and lockwashers.

(4) Connect motor electrical connector.

(d) Refer to figure 4-6 and install evapo-

(5) Refer to figure 4-2 and install housing

rator drain piping.

covers.

(e) Connect motor electrical connector.

MAINTENANCE OF FAN MOTOR SWITCHES

Section XIV.

(1) Refer to figrure 4-5 and remove rear top

4-39.

Evaporator Fan Motor Speed

cover.

Control Switch.

The evaporator fan motor speed control switch is

(2) Disconnect electrical connector located

just below condenser motor electrical connecter

a toggle switch which is part of the control module.

(fig. 4-12).

Replacement instructions for this switch are in-

(3) Check for continuity between terminals of

cluded with the control module.

connector. There should be no continuity between

terminals when temperature is below 95F (35C).

4-40.

Condenser Fan Motor Speed

If a source of heated air is available, check for

Control.

closing of contacts and continuity between termi-

a. General. The condenser fan motor speed con-

nals at 95F to 105F (35C to 40.6C).

trol thermostatic switch, located on the rear wall of

(4) If switch and connector assembly do not

the housing, automatically controls the fan motor

meet requirements, check wiring and repair dam-

speed. The switch is normally open and closes on

aged wiring or replace switch.

temperature rise between 95F and 105F (35C

c. Removal. With top cover removed and elec-

and 40.6C). When the switch contacts close the

trical connector disconnected, proceed as follows:

condenser fan relay coil is energized and the relay

(1) Refer to figure 4-15 and remove two

shifts the fan motor circuit from low-speed to high-

screws and lockwashers. Remove switch and con-

speed.

nector assembly.

b. Testing. Test the switch and connector as-

(2) Disconnect switch leads from connector.

sembly in the air conditioner as follows:

4-31