Discovery electrical Manual - part 63

 

  Index      Land Rover     DISCOVERY ELECTRICAL TROUBLESHOOTING MANUAL 1997-1999 year

 

Search            

 

 

 

 

 

 

 

 

 

Content   ..  61  62  63  64   ..

 

 

Discovery electrical Manual - part 63

 

 

COMPRESSOR CONTROLS (MFI–V8)

K2

5

CIRCUIT DIAGRAM

S296

30

F 3

30 A

E100

See Fuse Details

5

C217

30

NG

[1]

[2]

30

87

86

85

86

C241

BG

85

C241

87

BS

33

C243

21

30

30

87

85

86

85

C242

86

C242

87

WG

3

C217

B

K2-4

YB

10

C217

YB

9

C2073

U

OG

1

C2076

K108
Compressor
Clutch Relay

K170
A/C Logic Relay

X101
Front A/C Evap-
orator Tempera-
ture Switch

[1]

> 0



C (32



F)

[2]

< 0



C (32



F)

Z132
Engine Control
Module (ECM)

1

C2077

8

C2073

ON

S295

1

C145

2

C145

B

B

K107
Compressor
Clutch

See Ground Dis-
tribution

1

C116

GY

P125
Engine Compart-
ment Fuse Box

E

K2-10

D

K2-11

6

C216

MFI–V8

COMPRESSOR CONTROLS (MFI–T16)

K2

6

CIRCUIT DIAGRAM

30

F 3

30 A

E100

See Fuse Details

5

C217

30

[1]

[2]

30

87

85

86

85

C241

BG

86

C241

87

BS

19

C1007

30

30

87

86

85

86

C242

85

C242

87

YB

10

C217

YB

9

C2073

U

OG

1

C2076

K108
Compressor
Clutch Relay

K170
A/C Logic Relay

X101
Front A/C Evap-
orator Tempera-
ture Switch

[1]

> 0



C (32



F)

[2]

< 0



C (32



F)

Z132
Engine Control
Module (ECM)

1

C2077

8

C2073

ON

S295

1

C145

2

C145

B

B

K107
Compressor
Clutch

See Ground Dis-
tribution

1

C116

P125
Engine Compart-
ment Fuse Box

E

K2-10

BN

D

K2-11

6

C216

WG

Z132
Engine Control
Module (ECM)

35

C1007

B

E100

See Ground Dis-
tribution

15

F 3

10 A

See Fuse Details

P127
Satellite Fuse
Box 1

S2034

WG

B

K2-4

WG

3

C217

Not used

W

NG

MFI–T16

COMPRESSOR CONTROLS (SFI–V8)

K2

7

CIRCUIT DIAGRAM

S295

30

F 3

30 A

1

C116

E102

See Fuse Details

P125
Engine Compart-
ment Fuse Box

NG

30

30

86

C241

BS

7

C1027

1

C1032

K108
Compressor
Clutch Relay

See Ground Dis-
tribution

WG

85

C241

87

87

BG

B

K2-4

28

C1017

YB

YB

9

C2073

U

1

C2076

X101
Front A/C Evapor-
ator Temperature
Switch

[1]

COOLING FANS

K5

CIRCUIT OPERATION

1

CIRCUIT OPERATION

Condenser Fan Operation (MFI–V8)

The Condenser Fans Motors (M113, M121) on
vehicles equipped with MFI–V8 engines operate
when any of the following conditions occur:

1. Coolant temperature exceeds 100



C (212



F).

2. The air conditioning system is operating.

3. The Engine Control Module (ECM) (Z132)

determines that fuel temperature exceeds
70



C and coolant temperature exceeds 110



C

after engine shutdown. When this occurs, the
fans are turned on for approximately 10 minutes
after the engine is shut off.

Operation with High Coolant Temperature

(MFI–V8)

When the Ignition Switch (X134) is in position II,
battery voltage is applied to the Ignition Load Relay
(K127). The relay is energised, applying battery
voltage to the Condenser Fan Relay (K109) and the
Fan Control Module (Z118). If the coolant
temperature exceeds 100



C (212



F), the Condenser

Fan Coolant Temperature Switch (X113) closes and
energises the Condenser Fan Relay (K109) by
applying ground to the relay’s coil. When the relay is
energised, voltage from fuse F3 is applied to the
Condenser Fan Motors (M113, M121) through the
relay’s contacts.

Fan Operation with A/C (MFI–V8)

With the Ignition Switch (X134) in position II, battery
voltage is applied to the Ignition Load Relay (K127).
The relay is energised, applying battery voltage to
the Condenser Fan Relay (K109). When the Front
A/C Switch (X225) is turned on and the Front Fan
Speed Switch (X247) is turned to positions I, II, III, or
IV, ground is applied to terminal 86 of the Condenser
Fan Relay. The relay energises, applying battery
voltage from fuse F3 to the Condenser Fan Motors
(M113, M121).

Operation with the Engine Off (MFI–V8)

The Engine Control Module (Z132) monitors fuel
temperature and coolant temperature through
sensors. When the ECM determines that fuel
temperature is above 70



C and coolant temperature

exceeds 110



C after engine shutdown, the ECM will

command fan operation for approximately 10

minutes. The ECM turns on the fans by momentarily
grounding the Fan Control Module (Z118) through
the BG wire. When the timer unit is grounded, it
starts a solid state timer and begins to apply ground
from its terminal 9 to the Condenser Fan Relay
(K109) through the BP wire. With the Condenser
Fan Relay energised, voltage from fuse F3 is applied
to the Condenser Fan Motors (M113, M121) through
the relay contacts.

 

 

 

 

 

 

 

Content   ..  61  62  63  64   ..