Inspection Procedure
- INSPECT FUSE (HTR)
- Remove the HTR fuse from the engine room No. 2 relay block.
- Measure the resistance of the fuse.
Standard resistance:
Below 1 Ω
NG: REPLACE FUSE
OK: Go to next step
- INSPECT HEATER RELAY (Marking: HTR)
- Remove the heater relay from the instrument panel junction block.
- Measure the resistance of the relay.
Standard resistance
RESISTANCE SPECIFICATIONTester Connection Specified Condition 3 - 4 Below 1 Ω 3 - 5 10 kΩ or higher 3 - 4 10 kΩ or higher (when battery voltage is applied to terminals 1 and 2) 3 - 5 Below 1 Ω (when battery voltage is applied to terminals 1 and 2)
NG: REPLACE HEATER RELAY
OK: Go to next step
- INSPECT BLOWER MOTOR
- Disconnect the E54 motor connector.
- Connect the positive (+) lead from the battery to terminal 2 and the negative (-) lead to terminal 1, then check that the blower motor operates smoothly.
OK:
The blower motor operates smoothly.
- Measure the current.
Standard current
TESTER CONNECTION AND SPECIFIED CONDITIONTester Connection Condition Specified Condition E54-1 - E54-2 Blower motor operates 1 to 3A
NG: REPLACE BLOWER MOTOR
OK: Go to next step
- CHECK WIRE HARNESS (HEATER CONTROL (BLOWER SWITCH) - BATTERY)
- Disconnect the E24 heater control connector.
- Measure the voltage of the wire harness side connector.
Standard voltage
VOLTAGE SPECIFICATIONTester Connection Condition Specified Condition E24-4 (LO) - Body ground Ignition switch ON 10 to 14 V
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step
- INSPECT HEATER CONTROL (BLOWER SWITCH)
- Remove the heater control.
- Measure the resistance of the switch.
Standard resistance
RESISTANCE SPECIFICATIONTester Connection Switch Position Specified Condition ALL - 5 (E) 0 10 kΩ or higher 4 (LO) - 5 (E) 1 Below 1 Ω 4 (LO) - 5 (E) - 9 (M1) 1 to 2 Below 1 Ω 4 (LO) - 5 (E) - 9 (M1) 2 Below 1 Ω 4 (LO) - 5 (E) - 9 (M1) - 10 (M2) 2 to 3 Below 1 Ω 4 (LO) - 5 (E) - 10 (M2) 3 Below 1 Ω 4 (LO) - 5 (E) -10 (M2) -6 (HI) 3 to 4 Below 1 Ω 4 (LO) - 5 (E) - 6 (HI) 4 Below 1 Ω
NG: REPLACE HEATER CONTROL
OK: Go to next step
- INSPECT BLOWER RESISTOR
- Remove the blower resistor.
- Measure the resistance of the resistor.
Standard resistance
RESISTANCE SPECIFICATIONTester Connection Specified Condition E55-4 (E) - E55-1 (HI) 3.12 to 3.60 Ω E55-4 (E) - E55-3 (M2) 1.45 to 1.67 Ω E55-4 (E) - E55-2 (M1) 0.52 to 0.60 Ω
NG: REPLACE BLOWER RESISTOR
OK: Go to next step
- CHECK WIRE HARNESS (HEATER CONTROL (BLOWER SWITCH) - BLOWER RESISTOR)
- Disconnect the E24 heater control connector.
- Disconnect the E55 blower resistor connector.
- Measure the resistance of the wire harness side connectors.
Standard resistance
RESISTANCE SPECIFICATIONTester Connection Specified Condition E24-6 (HI) - E55-1 (HI) Below 1 Ω E24-9 (M1) - E55-2 (M1) Below 1 Ω E24-10 (M2) - E55-3 (M2) Below 1 Ω E24-5 (E) - Body ground Below 1 Ω E55-4 (E) - Body ground Below 1 Ω
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step
- CHECK WIRE HARNESS (BLOWER RESISTOR - BLOWER MOTOR)
- Disconnect the E55 blower resistor connector.
- Disconnect the E54 motor connector.
- Measure the resistance of the wire harness side connectors.
Standard resistance
RESISTANCE SPECIFICATIONTester Connection Specified Condition E55-4 (E) - E54-1 Below 1 Ω
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step
- CHECK WIRE HARNESS (BLOWER MOTOR - BODY GROUND)
- Disconnect the E54 motor connector.
- Measure the resistance of the wire harness side connector.
Standard resistance
RESISTANCE SPECIFICATIONTester Connection Specified Condition E54-2 - Body ground Below 1 Ω - Measure the voltage of the Wire harness side connector.
Standard voltage
VOLTAGE SPECIFICATIONTester Connection Condition Specified Condition E54-2 - Body ground Ignition switch ON Heater control (blower switch) 1 10 to 14 V
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step
- CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BATTERY)
- Disconnect the E36 amplifier connector.
- Measure the voltage of the wire harness side connector.
Standard voltage
VOLTAGE SPECIFICATIONTester Connection Condition Specified Condition E36-21 (SBLW) - Body ground Ignition switch ON Heater control (blower switch) 0 10 to 14 V
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step
- CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BODY GROUND)
- Disconnect the E36 amplifier connector.
- Measure the resistance of the wire harness side connector.
Standard resistance
RESISTANCE SPECIFICATIONTester Connection Specified Condition E36-24 (GND) - Body ground Below 1 Ω
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE