Acura RL (1996-2004 year). Manual - part 64

+

–

63-1

Fans

9

)

(’96-’03 20)

A/C
ON
output

C328

PHOTO 72
VIEW 48

A/C
PRESSURE
SWITCH
A: High-low
B: Middle

PHOTO 1

BLK/YEL

2

7

C

FAN
CONTROL
UNIT

PHOTO 103
VIEW 52

C328

PHOTO 72
VIEW 48

(

*

7)
9

)

5

LT GRN/

BLK

2

1

RADIATOR
FAN 
CONTROL
SENSOR

PHOTO 60

12

GRN/BLK

POWERTRAIN
CONTROL
MODULE
(PCM)

PHOTO 104

VIEW 115

2

4

C201

PHOTO 112
VIEW 71

2

3

3

1

G402

PHOTO 106

YEL/BLK

BLK

BLU/

ORN

10

A/C
on
input
(ACS)

5

C201

PHOTO 112
VIEW 71

RED/WHT

See Power
Distribution,
page 10-6.

10

C502

(Not
used)

C920
OPTION
CONNECTOR

UNDER-DASH
FUSE/RELAY
BOX

PHOTO 75

GRN/RED

3

8

PNK

2

A/C
pressure
switch
input
(PDSW)

3

6

CLIMATE
CONTROL
UNIT

PHOTO 201 (’04)
VIEW 103

12

B

C446

PHOTO 108
VIEW 79

See  Ground
Distribution.
page 14-13.

G201

PHOTO 19

BLK

1

4

BLK

BLK

YEL/BLK

YEL/BLK

C403

PHOTO 74
VIEW 90

BLK/YEL

BLK/YEL

GRN/RED

GRN/RED

GRN/RED

GRN/BLK

RED/WHT

GRN/BLK

BLU/GRN

BLK

LT GRN/BLK

A/C ON
output

Condenser
fan relay
control

Radiator
fan main
relay
control

Ground

Radiator
fan control
sensor input

Sensor
ground

High-low
pressure
switch
input

Middle
pressure
switch 
input

Ignition
input

A

B

(

*

4)
5

)

(

*

3)
4

)

*

 = ‘96-’98

See Ground
Distribution,
page 14-2.

GRN/BLK

2004 American Honda Motor Co., Inc.

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63-2

Fans

How the Circuit Works

The radiator and condenser fan operation is
controlled by the fan control unit and receives
battery voltage through fuse 3. The fan control
unit receives input from the radiator fan control
sensor, the A/C pressure switch, and the climate
control unit.

The fan control unit turns on the radiator fan and
condenser fan based on input from the radiator
fan control sensor. Both fans operate when the
A/C is on.

Battery voltage is applied to the radiator fan relay
contacts through fuse 47 at all times. With the
ignition switch in ON (II), battery voltage is
applied to the radiator fan relay coil and the
radiator fan main relay coil through fuse 3.

Battery voltage is applied to the condenser fan
relay contacts through fuse 50 at all times. With
the ignition switch in ON (II), battery voltage is
applied to the condenser fan relay coil through
fuse 3.

Low Speed

When the radiator temperature reaches 84

°

 C

(183

°

 F), the fan control unit energizes the

condenser fan relay. Battery voltage is applied to
the condenser fan motor and the radiator fan
motor in series through the normally closed
contacts of the radiator fan main relay. Both fans
then run at low speed. When the radiator fan
temperature drops below 78

°

C (172

°

 F), the fan

control module deenergizes and both fans are
turned off.

High Speed

When the radiator temperature reaches 90

°

 C

(194

°

 F), the fan control unit energizes the

condenser fan relay, the radiator fan relay, and
the radiator fan main relay. Battery voltage is
applied to the condenser fan motor and is
grounded by the radiator fan main relay. The
condenser fan then runs at high speed.  At the
same time, the fan control module energizes the
radiator fan control module. The radiator fan
motor runs at high speed.

When the radiator fan temperature drops below
84

°

 C (183

°

 F), the fan control module runs the

fans at low speed by deenergizing the radiator
fan relay and the radiator fan main relay.

Refer to the Service Manual (Section 10, Fan
Controls) for specific tests or troubleshooting
procedures.

2004 American Honda Motor Co., Inc.

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64

Rear Window Defogger

UNDER-DASH
FUSE/RELAY
BOX

PHOTO 75

WHT/

GRN

FUSE 33

REAR 
DEFROSTER
40A

C305

PHOTO 36
VIEW 20

1

UNDER-HOOD
FUSE/RELAY
BOX

PHOTO 33

REAR
WINDOW
DEFOGGER

YEL/BLU

YEL/BLU

REAR
WINDOW
DEFOGGER
RELAY

PHOTO 25

3

1

2

1

B

2

A

REAR WINDOW

DEFOGGER COIL

PHOTO 154

BLK

5

C327

PHOTO 73
VIEW 89

2

YEL/GRN

YEL/GRN

C324

PHOTO 72
VIEW 21

2

C442

PHOTO 108
VIEW 92

15

YEL/BLU

YEL/BLU

C402

PHOTO 77
VIEW 37

2

C456
(Terminals 7-10)

PHOTO 103
VIEW 81

YEL/BLK

YEL/BLK

YEL/BLK

YEL/BLK

See Power
Distribution,
page 10-7.

PASSENGER’S
MULTIPLEX
CONTROL
UNIT

PHOTO 107
VIEW 112

3

2

19

See Ground
Distribution,
page 14-12.

G402

PHOTO 106

“ON”
INDICATOR
LIGHT

YEL/GRN

6

5

BLK

BLK

BLK

FUSE 19

R/C MIRROR
7.5A

See Power
Distribution,
page 10-7.

UNDER-HOOD
RELAY BOX A

PHOTO 23

A

PHOTO 119

B

PHOTO 121

Rear window
defogger ON
output

Ground

YEL/GRN

YEL/BLK

C327

PHOTO 73
VIEW 89

5

Except ’99-’04 (Navigation)

A

A

A

A

HOT IN ON

HOT AT ALL TIMES

2004 American Honda Motor Co., Inc.

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+

–

64-1

Rear Window Defogger

Except ’99-’04 (Navigation)

See Ground
Distribution,
page 14-4
or 14-8.

UNDER-DASH

FUSE/RELAY BOX

PHOTO 75

C404

PHOTO 76
VIEW 49

8

YEL

6

9

PASSENGER’S

MULTIPLEX

CONTROL

UNIT

PHOTO 107

VIEW 112

A

14

10

22

A

REAR
WINDOW
DEFOGGER
SWITCH
LIGHT

OFF

ON

3

See Ground
Distribution,
page 14-13.

4

BLK

G402

PHOTO 106

See Dash
and Console
Lights

2

YEL/BLU

RED

See Dash
and Console
Lights

RED/BLK

See Power
Distribution,
page 10-10.

YEL

RED/YEL

BRN/WHT

PNK/BLU

DRIVER’S

MULTIPLEX

CONTROL

UNIT

PHOTO 79

VIEW 114

A

See Ground
Distribution,
page 14-4
or 14-8.

FUSE 13

METER (

*

)

METER
SUN ROOF (

**

)

7.5A

See Power
Distribution,
page 10-10.

A

8

10

9

22

C448
(Terminals 14-16)

PHOTO 111
VIEW 80

13

B

G401 (

*

)

PHOTO 79

G251 (

**

)

PHOTO 46

1

BLK

BLK

BLK

REAR
WINDOW
DEFOGGER
SWITCH

VIEW 16

C406

PHOTO 74
VIEW 3

4

Rear window
defogger ON
input

Ignition
input

Wakeup

D-A
line

A-D
line

Ignition
input

Wakeup

D-A
line

A-D
line

Ground

*

= ‘96-‘98

**

= ’99-’04

HOT IN ON OR START

2004 American Honda Motor Co., Inc.

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