Toyota 4Runner manuals

Toyota 4Runner: IG Power Source Circuit

DESCRIPTION

The main power source is supplied to the air conditioning amplifier assembly when the ignition switch is turned to ON. The power source is used for operating the air conditioning amplifier assembly, servo motors, etc.

WIRING DIAGRAM


CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT:

Start the engine before inspection. Check the relays, fuses and battery if the engine does not start.

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BATTERY AND BODY GROUND)

(a) Disconnect the F42 amplifier connector.


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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

F42-1 (IG+) - Body ground

Ignition switch off

Below 1 V

Ignition switch ON

11 to 14 V

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

F42-14 (GND) - Body ground

Always

Below 1 Ω

Text in Illustration

*a

Rear view of wire harness connector

(to Air Conditioning Amplifier Assembly)


OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE


NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

PTC Heater Circuit
DESCRIPTION PTC heater relays are closed in accordance with signals from the air conditioning amplifier assembly and power is supplied to the quick heater assembly installed on the radiator heate ...

Back-up Power Source Circuit
DESCRIPTION The back-up power source circuit for the air conditioning amplifier assembly is shown below. Power is supplied even after the ignition switch is turned off and is used for diagnostic ...

Other materials about Toyota 4Runner:

Automatic running boards
The Automatic running boards are linked to the side door operations, extending and retracting when a side door is opened and closed. When a door is opened or closed, the board on the same side extends or retracts. 1. Opening a door: The appropriate boar ...

General Maintenance
GENERAL MAINTENANCE PROCEDURE 1. INSPECT STEERING LINKAGE AND GEAR HOUSING (a) Check the steering wheel free play. (b) Check the steering linkage for looseness or damage. (1) Check that the tie rod ends do not have excessive play. (2) Check that the dust ...

© 2016-2025 | www.to4runner.net

0.012