Lexus RX300 (MCU15). Service manual - part 100

AC3AW–01

I07794

1

2

3

4

I08493

Magnetic Clutch Control:

Low Pressure Side

ON (Continuity)

196 kPa

(2.0 kgf/cm

2

, 

28 psi)

OFF (No Continuity)

High Pressure Side

3,140 kPa

(32.0/kgf·cm

2

, 

455 psi)

OFF (No Continuity)

22.5 kPa

(2.3 kgf/cm

2

, 33 psi)

ON (Continuity)

(26 kgf/cm

2

, 

370 psi)

2,250 kPa

I05079

Condenser Fan Control

ON

(No Continuity)

(Continuity)

OFF

1,373 kPa

(14.0 kgf/cm

2

, 199 psi)

1,765 kPa

(18.0 kgf/cm

2

, 256 psi)

AC–68

–

AIR CONDITIONING

PRESSURE SWITCH

LEXUS RX300   (RM785E)

PRESSURE SWITCH

ON–VEHICLE INSPECTION

1.

SET VEHICLE IN THESE CONDITION

2.

RUNNING ENGINE AT 1,500 rpm

3.

BLOWER SPEED CONTROL SWITCH AT ”HI” POSI-
TION

4.

TEMPERATURE CONTROL DIAL AT ”MAX. COOL”
POSITION

5.

SET ON MANIFOLD GAUGE SET

6.

INSPECT PRESSURE SWITCH OPERATION

(a)

Disconnect the connector.

(b)

Inspect pressure switch continuity 
(Magnetic Clutch Control)
(1)

Connect the positive (+) lead from the ohmmeter to
terminal 4 and the negative (–) lead to terminal 1.

(2)

Check continuity between terminals when refriger-
ant pressure is changed, as shown in the illustra-
tion.

If continuity is not as specified, replace the pressure switch.

(c)

Inspect pressure switch continuity 
(Condenser Fan  Control)
(1)

Connect the positive (+) lead from the ohmmeter to
terminal 2 and the negative (–) lead to terminal 3.

(2)

Check continuity between terminals when refriger-
ant pressure is changed, as shown in the illustra-
tion.

If operation is not as specified, replace the pressure switch.

AC1NJ–01

I07793

–

AIR CONDITIONING

PRESSURE SWITCH

AC–69

LEXUS RX300   (RM785E)

REMOVAL

1.

DISCHARGE REFRIGERANT FROM REFRIGERATION
SYSTEM

HINT:
At the time of installation, please refer to the following item.
Evacuate air from refrigeration system.
Charge system with refrigerant and inspect for leakage of refrig-
erant.

Specified amount: 650 ± 50 g (22.92 ± 1.76 oz.)

2.

REMOVE PRESSURE SWITCH FROM LIQUID TUBE

Disconnect the connector and remove the pressure switch.

Torque: 10 N·m (100 kgf·cm, 7 ft·lbf)

HINT:

S

Lock the switch mount on the tube with an open end
wrench, being careful not to deform the tube, and remove
the switch.

S

At the time of installation, please refer to the following
item.
Lubricate a new O–ring with the compressor oil and install
the switch.

AC1NK–01

AC–70

–

AIR CONDITIONING

PRESSURE SWITCH

LEXUS RX300   (RM785E)

INSTALLATION

Installation is in the reverse order of removal (See page AC–69).

I19411

RHD model:

HEATER Relay

AC3AX–01

N23635

1

2

3

4

5

–

AIR CONDITIONING

HEATER MAIN RELAY

AC–71

LEXUS RX300   (RM785E)

HEATER MAIN RELAY

INSPECTION

1.

LHD model:
REMOVE LOWER FINISH PANEL

2.

RHD model:
REMOVE NO. 2 LOWER PANEL

3.

REMOVE HEATER MAIN RELAY

4.

INSPECT HEATER MAIN RELAY CONTINUITY

Condition

Tester connection

Specified condition

Constant

1 – 2

3 – 4

Continuity

Apply B+ between

terminals 1 and 2

3 – 5

Continuity

If continuity is not as specified, replace the relay.
5.

LHD model:
INSTALL LOWER FINISH PANEL

6.

RHD model:
INSTALL NO. 2 LOWER PANEL