Blower Motor Circuit

AIR CONDITIONING: AIR CONDITIONING SYSTEM: Blower Motor Circuit

Blower Motor Circuit

DESCRIPTION

When the heater control (blower switch) is set to position 1 or higher, the contact of the HTR relay is closed, current flows to the blower motor, and the blower motor operates. The blower motor speed can be changed by exchanging the ground and the blower resistor circuit with the heater control (blower switch).

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSES (GAUGE, HTR)

(a) Remove the HTR fuse from the engine room relay block.
(b) Remove the GAUGE fuse from the main body ECU.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:

(d) Reinstall the GAUGE fuse.
(e) Reinstall the HTR fuse.
NG -- REPLACE FUSE
OK -- Continue to next step.
2. INSPECT HTR RELAY

(a) Remove the HTR relay from the main body ECU.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

(a) Remove the blower motor Removal.
(b) Apply battery voltage to the terminals and check that the blower motor operates.
OK:

(c) Reinstall the blower motor.
NG -- REPLACE BLOWER MOTOR
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (HTR FUSE - MAIN BODY ECU)

(a) Disconnect the 4L main body ECU connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:

(c) Reconnect the main body ECU connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. INSPECT MAIN BODY ECU

(a) Remove the HTR relay from the main body ECU.
(b) Disconnect the 4E and 4F main body ECU connectors.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:

(d) Reconnect the main body ECU connectors.
(e) Measure the voltage according to the value(s) in the table below.
Standard voltage:

(f) Reinstall the HTR relay.
(g) Measure the voltage according to the value(s) in the table below.
Standard voltage:

NG -- REPLACE MAIN BODY ECU
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - NO. 2 HEATER CONTROL)

(a) Disconnect the G1 No. 2 heater control connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:

(c) Reconnect the No. 2 heater control connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BLOWER MOTOR)

(a) Disconnect the G4 blower motor connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:

(c) Reconnect the blower motor connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (BLOWER RESISTOR - BLOWER MOTOR)

(a) Disconnect the G3 blower resistor connector.
(b) Disconnect the G4 blower motor connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:

(d) Reconnect the blower resistor connector.
(e) Reconnect the blower motor connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. INSPECT BLOWER RESISTOR

(a) Remove the blower resistor Removal.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

(c) Reinstall the blower resistor.
NG -- REPLACE BLOWER RESISTOR
OK -- Continue to next step.
10. INSPECT NO. 2 HEATER CONTROL (BLOWER SWITCH)

(a) Remove the No. 2 heater control Disassembly.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

(c) Reinstall the No. 2 heater control.
NG -- REPLACE NO. 2 HEATER CONTROL
OK -- Continue to next step.
11. CHECK HARNESS AND CONNECTOR (NO. 2 HEATER CONTROL - BLOWER RESISTOR)

(a) Disconnect the G1 No. 2 heater control connector.
(b) Disconnect the G3 blower resistor connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:

(d) Reconnect the No. 2 heater control connector.
(e) Reconnect the blower resistor connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (BLOWER RESISTOR - BODY GROUND)