Lexus ES300 (1997 year). Manual - part 451

I00347

HR(+)

(–)

–

DIAGNOSTICS

AIR CONDITIONING SYSTEM

DI–581

733

1997 LEXUS ES300   (RM511U)

INSPECTION PROCEDURE

1

Check voltage between terminal HR of A/C control assembly connector and body
ground.

PREPARATION:
(a)

Remove front ash receptacle (See page 

BO–79

).

(b)

Remove A/C control assembly with connectors still con-
nected (See page 

BO–79

).

CHECK:
Measure voltage between terminal HR of A/C control assembly
and body ground when ignition switch is ON and OFF.
OK:

Ignition Switch

Voltage

OFF

0V

ON

Blower ON

0 V

ON

Blower OFF

10 – 14 V

OK

Proceed to next circuit inspection shown on
matrix chart (See page 

DI–535

).

NG

BE1850 BE1844

I00312

3

4

5

1

2

3

4

5

1

2

I00348

Instrument Panel J/B

HEATER

DI–582

–

DIAGNOSTICS

AIR CONDITIONING SYSTEM

734

1997 LEXUS ES300   (RM511U)

2

Check heater main relay.

PREPARATION:
Remove heater main relay from .
CHECK:
Check continuity between each pair of terminals of heater main
relay shown below.
OK:

Tester connection

Specified condition

1 – 4

No continuity

2 – 4

Continuity

3 – 5

62.5 – 90.9 

Ω

PREPARATION:
Apply battery positive voltage between terminals 3 and 5.
CHECK:
Check continuity between each pair of terminal shown below.
OK:

Tester connection

Specified condition

1 – 2

Continuity

2 – 4

No continuity

NG

Replace heater main relay.

OK

3

Check HEATER

PREPARATION:
Remove HEATER fuse from instrument panel J/B.
CHECK:
Check continuity of HEATER fuse.
OK:

There is continuity.

NG

Check for short in all the harness and compo-
nents connected to the HEATER fuse
(See page 

DI–583

).

OK

Check and repair harness and connector be-
tween A/C control assembly and battery.

I00345

A/C Control Assembly

BLW

Blower Motor

1

2

B–W

L–R

IH1

IH1

1

5

Blower Motor
Controller

4

3

2

1

IH1

2

J15

A

A

B–W

IH1

6

A14

16

II

I00346

1

2

–

DIAGNOSTICS

AIR CONDITIONING SYSTEM

DI–583

735

1997 LEXUS ES300   (RM511U)

Blower Motor Circuit

CIRCUIT DESCRIPTION

This is the power source for the blower motor.

WIRING DIAGRAM

INSPECTION PROCEDURE

1

Check blower motor.

PREPARATION:
Remove blower motor (See page 

AC–61

).

CHECK:
Connect positive (+) lead connected to terminal 2 of blower mo-
tor connector, negative (–) lead to terminal 1.
OK:

Blower motor  operates smoothly.

NG

Replace blower motor.

OK

DI0DO–01

DI–584

–

DIAGNOSTICS

AIR CONDITIONING SYSTEM

736

1997 LEXUS ES300   (RM511U)

2

Check harness and connector between battery and blower motor, blower motor
and body ground. (See page 

IN–27

).

NG

Repair or replace harness or connector.

OK

Proceed to next circuit inspection shown on
matrix chart (See page 

DI–535

).