Land Rover Discovery 99my To 03my Electrical Library 3rd Edition Rover Manual

DESCRIPTION AND OPERATION
4.90DISCOVERY SERIES II
OPERATION
Cooling Fan Supply
Circuit supply
A permanent feed from the battery positive terminal is connected by an R wire to the engine 
compartment fusebox. A feed from this wire is connected to the contacts of the main relay 
and also to fuse 13. The feed passes through fuse 13 and to the inertia switch on a NB wire. 
The feed from the inertia switch flows on a WG wire to the engine compartment fusebox and 
is connected to the coils of the main relay....

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.91
Td5 engine
The engine coolant temperature sensor sends an input on a KG wire to pin C0158-7 on the 
ECM. The engine coolant temperature sensor is earthed on a KB wire to pin C0158-18 on 
the ECM.
When the coolant temperature is high, the value of input from the coolant temperature 
sensor causes the ECM logic to switch on the earth path for the coil of the cooling relay, on 
a BP wire to pin C0658-4 on the ECM. With the coil of the cooling relay earthed...

DESCRIPTION AND OPERATION
4.92DISCOVERY SERIES II
HEATED REAR WINDOW (HRW)
DESCRIPTION
General
The HRW is operated from a non-latching switch located to the left of the instrument pack. 
The switch has an indicator light to show when the HRW is operating. The HRW element 
comprises fourteen metallic strips bonded to the inside surface of the rear window. The 
HRW will only function when the engine is running due to the high current draw and 
subsequent load on the battery.
The HRW can also be operated by...

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.93
Heated Rear Window Switch Operation
When the HRW switch is operated, an earth path is completed from the HRW switch to earth 
header C0017 LHD/C0018 RHD on a B wire, via header C0760.
The completion of the earth path from the HRW switch, completes an earth path from the 
BCU to the switch on an NB wire. The earth path completes a circuit within the BCU for an 
internal electronic switch which receives its feed from fuse 29 in the passenger compartment...

DESCRIPTION AND OPERATION
4.94DISCOVERY SERIES II
Air Temperature Control (ATC) ECU Operation
On vehicles fitted with air conditioning, the HRW can be operated when DEF, feet/screen 
or screen is selected on the ATC control panel.
When one of the above selections is made, the ATC ECU provides a feed to the HRW switch 
into the NP wire from the BCU to the HRW switch. This illuminates the switch indicator light.
Simultaneously, the ATC ECU also provides an earth path into the NB wire from the BCU to 
the...

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.95
HEATED FRONT SCREEN (HFS)
DESCRIPTION
General
The heated front screen (HFS) is operated from a non-latching switch located to the left of 
the instrument pack. The switch has an indicator light to show when the HFS is operating. 
The HFS comprises two elements laminated in the screen, each element being controlled 
by a separate fuse. The HFS will only function with the engine running, due to the high 
current draw and subsequent load on the battery.
The...

DESCRIPTION AND OPERATION
4.96DISCOVERY SERIES II
In this condition, the auxiliary circuits relay coil is energised and the contacts close. The relay 
coil is earthed to earth header C0018 on a B wire from the engine compartment fusebox, via 
header C0286 LHD/C0288 RHD.
When the ignition switch is in position II, the feed from fusible link 8 flows through the ignition 
switch to the passenger compartment fusebox on a Y wire. The feed continues through fuse 
29 in the passenger compartment fusebox and is...

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.97
Air Temperature Control (ATC) ECU operation
On vehicles fitted with air conditioning, the HFS can be operated when DEF, feet/screen 
or screen is selected on the ATC control panel.
When one of the above selections is made, the ATC ECU provides a feed to the HFS switch 
into the PS wire from the BCU to the switch. This illuminates the HFS switch indicator light.
Simultaneously, the ATC ECU also provides an earth path into the KO wire from the BCU to 
the...

DESCRIPTION AND OPERATION
4.98DISCOVERY SERIES II
FRONT WIPERS AND WASHERS
DESCRIPTION
General
The front wipers and washers are operated from a switch stalk located on the right hand side 
of the steering column and operate with the ignition switch in positions I or II. The wipers are 
operated by a wiper motor located below the windscreen plenum. The washers and optional 
headlamp power washers are operated from electric pumps attached to the washer 
reservoir located in the left hand wheel arch.
The...

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.99
OPERATION
Front Wipers and Washers Supply
Circuit supply
A feed from the battery positive terminal is connected on an R wire to the engine 
compartment fusebox, where it passes through fusible links 1, 7, 8, 10 and fuse 4. Fusible 
link 1 and fuse 4 and fusible links 1 and 7 are connected in series.
A feed from fusible link 1 and fuse 4 is connected to the contacts of the power wash relay 
located in the engine compartment fusebox (P108).
A feed from...