Blower Motor Circuit

AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System): Blower Motor Circuit
- Blower Motor Circuit

DESCRIPTION

The blower motor is operated by signals from the air conditioning amplifier. Blower motor speed signals are transmitted in accordance with changes in the duty ratio.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON and turn the Techstream ON.

(c) Select the item below in the Active Test, and then check that the blower motor operates.

Air conditioning amplifier:





Result:





C -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

B -- CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BODY GROUND)
A -- Continue to next step.

2. INSPECT FUSE (HTR)

(a) Remove the HTR H-fuse from the engine room No. 2 relay block.

(b) Measure the resistance of the H-fuse.

Standard resistance:

Below 1 Ohms

NG -- REPLACE FUSE
OK -- Continue to next step.

3. CHECK WIRE HARNESS (BLOWER MOTOR - BODY GROUND)





(a) Disconnect the E53 motor connector.

(b) Measure the resistance of the wire harness side connector.

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

4. CHECK WIRE HARNESS (BLOWER MOTOR - BATTERY)





(a) Disconnect the E53 motor connector.

(b) Measure the voltage of the wire harness side connector.

Standard voltage:





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

5. CHECK BLOWER W/ FAN MOTOR SUB-ASSEMBLY





(a) Disconnect the E37 amplifier connector.

(b) Connect the E53 motor connector.

(c) Measure the voltage of the connector.

Standard voltage:





NG -- REPLACE BLOWER W/ FAN MOTOR SUB-ASSEMBLY
OK -- Continue to next step.

6. CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BODY GROUND)





(a) Disconnect the E37 amplifier connector.

(b) Measure the voltage of the wire harness side connector.

Standard voltage:





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

7. CHECK AIR CONDITIONING AMPLIFIER





(a) Remove the air conditioning amplifier with its connectors still connected.

(b) Check the waveform of the amplifier connector.

OK:

Waveform is as shown in the illustration.

HINT
The waveform varies with the blower level.





NG -- REPLACE AIR CONDITIONING AMPLIFIER

OK -- REPLACE BLOWER W/ FAN MOTOR SUB-ASSEMBLY