Inspection Procedure

1. Remove the GAUGE fuse from the driver side junction block.
2. Remove the HTR H-fuse from the engine room junction block.
3. Measure the resistance of the fuses.

   Standard resistance: Below 1 Ω 

NG : REPLACE FUSE 

OK : GO TO NEXT STEP 

1. Remove the heater relay from the driver side junction block.
2. Measure the resistance of the relay.

   Standard resistance 

   TERMINALS RESISTANCE SPECIFICATIONS
   
   

   Tester Connection	Specified Condition
   3 - 5	10 kΩ or higher
   3 - 5	Below 1 Ω (When battery voltage applied to terminals 1 and 2)
   3 - 4	Below 1 Ω
   3 - 5	10 kΩ or higher (When battery voltage applied to terminals 1 and 2)

NG : REPLACE HEATER RELAY 

Fig 1: Inspecting Heater Relay

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : GO TO NEXT STEP 

1. Disconnect the A8 amplifier connector.
2. Measure the voltage of the wire harness side connector.

   Standard voltage 

   TERMINALS VOLTAGE SPECIFICATIONS
   
   

   Tester Connection	Condition	Specified Condition
   A8-7 (HR) - Body ground	Power switch ON (IG)	10 to 14 V

NG : REPAIR OR REPLACE HARNESS AND CONNECTOR 

Fig 2: Disconnecting A8 Amplifier Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : GO TO NEXT STEP 

1. Remove the air conditioning amplifier with connectors still connected.
2. Measure the voltage of the connector.
   Fig 3: Disconnecting A8 Amplifier Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard voltage 

   TERMINALS VOLTAGE SPECIFICATIONS
   
   

   Tester Connection	Condition	Specified Condition
   A8-7 (HR) - Body ground	Power switch OFF Blower switch position ON	Below 1 V
   A8-7 (HR) - Body ground	Power switch ON (IG) Blower switch position ON	Below 1 V
   A8-7 (HR) - Body ground	Power switch ON (IG) Blower switch position OFF	10 to 14 V

NG : REPLACE AIR CONDITIONING AMPLIFIER 

OK : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE