AC HEATER/EVAPORATOR BLOWER DOES NOT OPERATE IN ALL SPEEDS (LOW, MEDIUM, AND HIGH) (Cont)

DRAFT

TB 9-2320-279-13-1

AC HEATER/EVAPORATOR BLOWER DOES NOT OPERATE IN ALL SPEEDS

(LOW, MEDIUM, AND HIGH) - Continued

WARNING

Remove rings, bracelets, wristwatches, neck chains, and any other jewelry before working around

vehicle. Jewelry can catch on equipment and cause serious injury. Jewelry or tools may short

across electrical circuits or terminals and cause damage to equipment or severe burns or

electrical shock to personnel.

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VOLTAGE TEST

(1) Disconnect fan control switch harness connector

(2) Turn engine start switch ON (TM 9-2320-279-10).

(3) Turn fan control switch to low speed position

(4) Place positive (+) probe of multimeter on red wire at

fan control switch harness connector, terminal 1.

(5) Place negative (-) probe of multimeter on a known

good ground.

(a) If 22 to 28 vdc are not measured, turn engine

start switch OFF and go to Step 8 of this fault.

(b) If 22 to 28 vdc are measured, turn engine start

switch OFF and go to Step 7 of this fault.

CONTINUITY TEST

(1) Disconnect AC heater/evaporator blower motor

resistor harness connector from AC heater/

evaporator blower motor resistor (WP 0036).

(2) Set multimeter switch to ohms.

(3) Place positive (+) probe of multimeter on AC heater/

evaporator blower motor resistor harness red wire

at AC heater/evaporator blower motor resistor

connector.

(4) Place negative (-) probe of multimeter on AC

heater/evaporator blower motor resistor harness red

wire at fan control switch harness connector,

terminal 1.

(a) If there is no continuity, repair AC heater/

evaporator blower motor resistor harness red

wire (see Appendix A) or replace AC heater/

evaporator blower motor resistor harness

(WP 0036). Verify repair, go to Step 15 of this

fault.

(b) If there is continuity, replace AC heater/

evaporator blower motor resistor (WP 0035).

HEMAC131

Verify repair, go to Step 15 of this fault.