Toyota 4Runner: Air Conditioning Compressor Magnetic Clutch Circuit

Toyota 4Runner Service Manual / Vehicle Interior / Heating / Air Conditioning / Air Conditioning System(for Manual Air Conditioning System) / Air Conditioning Compressor Magnetic Clutch Circuit

DESCRIPTION

When the air conditioning amplifier assembly is turned on, a magnet clutch assembly ON signal is sent from the MGC terminal of the air conditioning amplifier assembly. Then, the A/C COMP relay turns on to operate the magnet clutch assembly.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

PROCEDURE

1.	INSPECT MAGNET CLUTCH RELAY (A/C COMP)

(a) Remove the A/C COMP relay from the engine room No. 1 relay block, junction block.

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

Standard Resistance:

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

REPLACE MAGNET CLUTCH RELAY (A/C COMP)

2.	INSPECT COOLER COMPRESSOR ASSEMBLY

(a) Remove the cooler compressor assembly (See page ).

(b) Disconnect the A magnet clutch connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
3 (MG+) - A-1	Always	Below 1 Ω
3 (MG+) - Body ground	Always	10 kΩ or higher

REPLACE COOLER COMPRESSOR ASSEMBLY

3.	INSPECT MAGNETIC CLUTCH ASSEMBLY

(a) Reconnect the A magnet clutch connector.

(b) Apply battery voltage to the magnet clutch assembly and check the operation of the magnet clutch assembly.

OK:

Measurement Condition	Specified Condition
Battery positive (+) → Terminal 3 (MG+) Battery negative (-) → Body ground	Magnet clutch assembly operating sound can be heard, and magnetic clutch hub and rotor lock.

Measurement Condition

Specified Condition

Battery positive (+) → Terminal 3 (MG+)

Battery negative (-) → Body ground

Magnet clutch assembly operating sound can be heard, and magnetic clutch hub and rotor lock.

REPLACE MAGNET CLUTCH ASSEMBLY

4.	CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK, JUNCTION BLOCK - BATTERY)

(a) Remove the A/C COMP relay from the engine room No. 1 relay block, junction block.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A/C COMP relay terminal 1 - Body ground	Ignition switch ON	11 to 14 V
A/C COMP relay terminal 5 - Body ground	Always	11 to 14 V

Text in Illustration

A/C COMP Relay

Component without relay installed

(Engine Room No. 1 Relay Block, Junction Block)

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BATTERY)

(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
F42-20 (MGC) - Body ground	Ignition switch off	Below 1 V
F42-20 (MGC) - Body ground	Ignition switch ON	11 to 14 V

Text in Illustration

*a	Front view of wire harness connector (to Air Conditioning Amplifier Assembly)

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK, JUNCTION BLOCK - COOLER COMPRESSOR)

(a) Remove the A/C COMP relay from the engine room No. 1 relay block, junction block.

(b) Disconnect the B41 compressor connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A/C COMP relay terminal 3 - B41-3 (MG+)	Always	Below 1 Ω
B41-3 (MG+) - Body ground	Always	10 kΩ or higher

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

REPAIR OR REPLACE HARNESS OR CONNECTOR

Air Conditioning Control Panel Circuit

DESCRIPTION This circuit consists of the heater control assembly and air conditioning amplifier assembly. When the heater control assembly is operated, signals are transmitted to the air conditio ...

Other materials about Toyota 4Runner:

Portable Player cannot be Connected Manually/Automatically
CAUTION / NOTICE / HINT HINT: Some versions of "Bluetooth" compatible audio players may not function, or the function may be limited using the radio and display receiver assembly, even if the portable audio player itself can play files (See pag ...

Problem Symptoms Table
PROBLEM SYMPTOMS TABLE HINT: Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" ...