Air Conditioning System (For Automatic Air Conditioning System) Heater Relay Circuit


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT NO. 1 HEATER RELAY

CHECK HARNESS AND CONNECTOR (NO. 1 HEATER RELAY - AIR CONDITIONING AMPLIFIER, BATTERY AND BODY GROUND)

CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System) - Heater Relay Circuit


DESCRIPTION

The No. 1 heater relay is turned on by signals from the air conditioning amplifier assembly. The No. 1 heater relay supplies power to the blower motor control.

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System).Air Conditioning System (For Automatic Air Conditioning System) Heater Relay Circuit


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
1.INSPECT NO. 1 HEATER RELAY


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System).Air Conditioning System (For Automatic Air Conditioning System) Heater Relay Circuit

  1. Remove the No. 1 heater relay from the driver side junction block assembly.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    3 - 4
    		Battery voltage is not applied to terminals 1 and 2
    		Below 1 Ω
    3 - 5
    		10 kΩ or higher
    3 - 4
    		Battery voltage is applied to terminals 1 and 2
    		10 kΩ or higher
    3 - 5
    		Below 1 Ω


NG
REPLACE NO. 1 HEATER RELAY
OK


2.CHECK HARNESS AND CONNECTOR (NO. 1 HEATER RELAY - AIR CONDITIONING AMPLIFIER, BATTERY AND BODY GROUND)

  1. Remove the No. 1 heater relay from the driver side junction block assembly.

  1. Disconnect the A38 air conditioning amplifier assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    No. 1 heater relay terminal 2 - A38-14 (HR)
    		Always
    		Below 1 Ω
    No. 1 heater relay terminal 2 - Body ground
    		Always
    		10 kΩ or higher
    No. 1 heater relay terminal 3 - Body ground
    		Always
    		10 kΩ or higher
    No. 1 heater relay terminal 4 - Body ground
    		Always
    		Below 1 Ω

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    No. 1 heater relay terminal 1 - Body ground
    		Ignition switch ON
    		11 to 14 V
    Ignition switch off
    		Below 1 V
    No. 1 heater relay terminal 5 - Body ground
    		Always
    		11 to 14 V


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System).Air Conditioning System (For Automatic Air Conditioning System) Heater Relay Circuit

  1. Remove the air conditioning amplifier assembly with its connectors still connected (Toyota Fortuner RM000001K3A018X.html).

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A38-14 (HR) - Body ground
    1. Ignition switch off
    2. Blower switch off
    		Below 1 V
    1. Ignition switch ON
    2. Blower switch on (LO level)
    		Below 1 V
    1. Ignition switch ON
    2. Blower switch off
    		11 to 14 V
    Text in Illustration
    *a
    		Component with harness connected
    (Air Conditioning Amplifier Assembly)


NG
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Toyota Fortuner RM000001K3A018X.html)
OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (Toyota Fortuner RM0000045E300YX.html)