EVAPORATOR FAN AND MOTOR ASSEMBLY. (B-3)

TM 5-4120-369-14

4-31.

RECTIFIER (CR-1) AND CAPACITORS (C-1 and C-2) - Continued.

(2) Using the ohms function of a multimeter, measure the resistance between the

+ and the - terminals of the rectifier:

(a) With the + lead of the meter on the - terminal of the rectifier and the

- lead of the meter on the + terminal of the rectifier, conductivity should be indicated.

(b) Reverse the meter leads to the rectifier; meter should indicate an open

circuit (infinity).

(3) Using multimeter, test capacitor for continuity. Replace capacitor if continuity

exists.

Installation.

(1) Refer to figure 4-21 and install rectifier.

(2) Refer to FO-1 and install capacitors by crimping leads into cable terminals.

(3) Refer to FO-1 and attach cable to rectifier.

(4) Refer to paragraph 4-27 and install the junction box.

EVAPORATOR FAN AND MOTOR ASSEMBLY. (B-3)

General. The evaporator fan motor is a multispeed motor. The motor operates at 3450

RPM in high speed and 1725 RPM in low speed operation and each winding is thermally protected,

Motor speed is manually controlled by the evaporator fan speed switch.

Controls. Before removing the evaporator fan and motor assembly, test the mode

selector s witch, evaporator fan speed switch, and control circuit breaker (paragraph 4-30) and

evaporator fan motor low/high speed switch (paragraph 4-30) which control operation of the motor.

If electrical control components or wiring that supply power to the motor are not defective and the

motor does not operate, proceed as follows:

Test.

Test the motor for open-circuit or grounded windings as follows.

(1) Using a multimeter, test at P3 for continuity across a combination of two leads

until each of the three high speed winding leads is tested. Do the same for the three low speed

winding leads. if continuity is not indicated, the winding is open and the motor should be

replaced.

(2) Using a multimeter, test for continuity by placing one test probe against the motor

housing (on bare metal only) and the other probe against each of the motor winding leads. If

continuity is indicated, the winding is grounded, and the motor should be replaced.