Blower Motor Circuit

AIR CONDITIONING: AIR CONDITIONING SYSTEM: Blower Motor Circuit

Blower Motor Circuit

DESCRIPTION





The blower motor is operated by signals from the A/C amplifier. Blower motor speed signals are determined by changes in the duty ratio*. The blower motor control controls the blower motor speed. The blower motor control reads the signal from the A/C amplifier and controls rotation and speed.
HINT: *: The duty ratio is the ratio of the blower motor ON time (A) to the total of the blower motor ON and OFF time (A+B).

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTUATOR CHECK (BLOWER LEVEL)
(a) Enter the actuator check mode Actuator Check.
(b) Press the blower switch to set the step operation.
(c) Check the air flow level by hand.






OK:
Blower level changes in accordance with each display code.
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
NG -- Continue to next step.
2. CHECK WIRE HARNESS (BLOWER MOTOR CONTROL - BATTERY)




(a) Disconnect the B6 control connector.
(b) Turn the ignition switch ON and push the AUTO switch.
(c) Measure the voltage of the connector.
Standard voltage:






NG -- INSPECT FUSE (HEATER)
OK -- Continue to next step.
3. INSPECT BLOWER W/ FAN MOTOR SUB-ASSEMBLY




(a) Remove the motor.
(b) Apply battery voltage to the motor and check that the motor rotates.
OK:






NG -- REPLACE BLOWER W/ FAN MOTOR
SUB-ASSEMBLY
OK -- Continue to next step.
4. CHECK WIRE HARNESS (BLOWER MOTOR CONTROL - BLOWER W/ FAN MOTOR)




(a) Disconnect the B7 control connector.
(b) Disconnect the B5 motor connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. CHECK WIRE HARNESS (BLOWER MOTOR CONTROL - A/C AMPLIFIER AND BODY GROUND)




(a) Disconnect the B6 control connector.
(b) Disconnect the A10 amplifier connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
6. CHECK BLOWER MOTOR CONTROL
(a) Check if the malfunction disappears when a functioning blower motor control is installed.
OK:
Blower motor operates normally.
NG -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
OK -- REPLACE BLOWER MOTOR CONTROL
7. INSPECT FUSE (HEATER)
(a) Remove the HEATER M-fuse from the engine room No. 1 junction block.
(b) Remove the HEATER fuse from the driver side junction block.
(c) Measure the resistance of the fuses.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.
8. INSPECT RELAY (Marking: HTR)




(a) Remove the HTR relay from the engine room No. 2 relay block.
(b) Measure the resistance of the relay.
Standard resistance:






NG -- REPLACE RELAY
OK -- Continue to next step.
9. CHECK WIRE HARNESS (PASSENGER SIDE JUNCTION BLOCK ECU - BATTERY)




(a) Disconnect the P6 ECU connector.
(b) Measure the voltage of the wire harness side connector.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE PASSENGER SIDE JUNCTION BLOCK (PASSENGER SIDE JUNCTION BLOCK ECU)