Blower Motor Circuit

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: Blower Motor Circuit
- Blower Motor Circuit

DESCRIPTION

The blower with fan motor sub-assembly (blower motor) is operated by signals from the air conditioning amplifier assembly. Blower motor speed signals are transmitted in accordance with changes in the duty ratio.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Air Conditioner / Active Test.

(e) Check the operation by referring to the table below.

Air Conditioner





OK:

Blower with fan motor sub-assembly (blower motor) operates and blower motor speed level changes.

Result:





B -- CHECK HARNESS AND CONNECTOR (BLOWER WITH FAN MOTOR (BLOWER MOTOR) - BODY GROUND)

C -- INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

A -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

2. CHECK HARNESS AND CONNECTOR (BLOWER WITH FAN MOTOR (BLOWER MOTOR) - BODY GROUND)

(a) Disconnect the L33 blower with fan motor sub-assembly (blower motor) connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





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

3. CHECK HARNESS AND CONNECTOR (BLOWER WITH FAN MOTOR (BLOWER MOTOR) - POWER SOURCE)

(a) Measure the voltage according to the value(s) in the table below.





Standard Voltage:





Text in Illustration





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

4. CHECK HARNESS AND CONNECTOR (BLOWER WITH FAN MOTOR - AIR CONDITIONING AMPLIFIER)

(a) Disconnect the L17 air conditioning amplifier assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





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

5. INSPECT BLOWER WITH FAN MOTOR SUB-ASSEMBLY (BLOWER MOTOR)

(a) Reconnect the L33 blower with fan motor sub-assembly (blower motor) connector.

(b) Measure the voltage according to the value(s) in the table below.





Standard Voltage:





Text in Illustration





NG -- REPLACE BLOWER WITH FAN MOTOR SUB-ASSEMBLY Disassembly
OK -- Continue to next step.

6. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

(a) Remove the air conditioning amplifier assembly.





(b) Reconnect the L17 air conditioning amplifier assembly connector.

(c) Turn the power switch on (IG).

(d) Set the blower speed to low.

(e) Measure the waveform between terminal L17-23 (BLW) of the air conditioning amplifier assembly and body ground.





OK:

Waveform is as shown in the illustration.

HINT
The waveform varies with the blower speed.

Text in Illustration





NG -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal

OK -- REPLACE BLOWER WITH FAN MOTOR SUB-ASSEMBLY Disassembly