Blower Motor Circuit

HEATING / 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 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 engine switch on (IG).

(c) Turn the Techstream on.

(d) Select the item below in the Active Test and then check that the relay operates.

Active Test / Air Conditioner





Result:





B -- INSPECT FUSE (HEATER)

C -- CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BODY GROUND)

A -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

2. INSPECT FUSE (HEATER)

(a) Remove the HEATER fuse from the engine room relay block and junction block No. 1.





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

Standard Resistance:





NG -- REPLACE FUSE (HEATER)
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - BODY GROUND)

(a) Disconnect the 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.

4. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - BATTERY)

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





Standard Voltage:





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

5. INSPECT BLOWER MOTOR

(a) Reconnect the blower motor connector.





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

Standard Voltage:





NG -- REPLACE BLOWER MOTOR Removal
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BODY GROUND)

(a) Disconnect the A/C amplifier connector.





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

Standard Voltage:





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

7. INSPECT A/C AMPLIFIER

(a) Remove the A/C amplifier.





(b) Reconnect the A/C amplifier connector.

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

(d) Turn the blower switch on (LO).

(e) Measure the waveform between terminal J58-11 (BLW) of the A/C amplifier and body ground.

OK:

Waveform is as shown in the illustration.

HINT
The waveform varies with the blower speed.





NG -- REPLACE A/C AMPLIFIER Removal

OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures