1999 LAND ROVER DISCOVERY alternator

PANEL REPAIRS
77-2-54 REPAIRS
Repair
1.Remove existing panel(s), prepare panel joint
faces and install new panel(s) in accordance
with Panel Replacement Procedure. Punch or
drill holes in new panel for plug welding as
shown.
2. During welding operations, apply 'Heat
shrink paste' to roof and body side panel to
avoid heat damage to paintwork.Refit
1.Fit and secure wiring.
2.Fit side and rear drip rail finishers.
3.Fit alpine light glass.

+ SCREENS, REPAIRS, Glass - alpine
light.
4.Fit windscreen.

+ SCREENS, REPAIRS, Windscreen.
5.Fit 'D' post outer trim finishers.
6.Fit rear door aperture seals.
7.Fit tread plates to rear door apertures.
8.Fit front door aperture seals.
9.Fit 'A' post lower trim panels.
10.Fit tread plates to front door apertures.
11.Fit roof bars.

+ EXTERIOR FITTINGS, REPAIRS,
Roof bars.
12.Fit rear headrests.
13.Fit rear seats.

+ SEATS, REPAIRS, Seat - rear.
14.Fit front seats.

+ SEATS, REPAIRS, Seat - front.
15. Models with fixed roof: Fit head lining.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Headlining.
16. Models with sunroof: Fit sunroof drain tubes.
17. Models with sunroof: Fit rear sunroof.

+ SUNROOF, REPAIRS, Sunroof -
rear.
18. Models with sunroof: Fit front sunroof.

+ SUNROOF, REPAIRS, Sunroof -
front.
19.Connect leads/multiplug to alternator.
20.Connect battery leads, negative lead last.
M77 1715A

HEATING AND VENTILATION
80-8DESCRIPTION AND OPERATION
Control panel
The controls for heating and ventilation are installed on a control panel in the centre of the fascia, below the radio.
Three rotary knobs control the LH and RH outlet temperatures and distribution. A slider switch controls blower speed.
A latching pushswitch controls the selection of fresh/recirculated air; an amber LED in the switch illuminates when
recirculated air is selected.
Graphics on the panel and the controls indicate the function and operating positions of the controls.
Outlet vent
The outlet vent promotes the free flow of heating and ventilation air through the cabin. The outlet vent is installed in
the RH rear quarter body panel and vents cabin air into the sheltered area between the rear quarter body panel and
the outer body side panel. The vent consists of a grille covered by soft rubber flaps and is effectively a non-return
valve. The flap opens and closes automatically depending on the differential between cabin and outside air pressures.
FBH system (diesel models only)
The FBH system is an auxiliary heating system that compensates for the relatively low coolant temperatures inherent
in the diesel engine. At low ambient temperatures, the FBH system heats the coolant supply to the heater assembly,
and maintains it within the temperature range required for good in-car heating performance. Operation is fully
automatic, with no intervention required by the driver.
The system consists of an air temperature sensor, a FBH fuel pump and a FBH unit. Fuel for the FBH system is taken
from the fuel tank, through a line attached to the fuel tank's fuel pump, and supplied via the FBH fuel pump to the FBH
unit. The connection on the fuel tank's fuel pump incorporates a tube which extends down into the tank. At the FBH
unit connection, the fuel line incorporates a self-sealing, quick disconnect coupling. In the FBH unit, the fuel delivered
by the FBH fuel pump is burned and the resultant heat output is used to heat the coolant. An ECU integrated into the
FBH unit controls the operation of the system at one of two heat output levels, 2.5 kW at part load and 5 kW at full load
Ambient temperature sensor
The ambient temperature sensor controls a power supply from the alternator to the FBH unit. The sensor is installed
on the RH support strut of the bonnet closing panel and contains a temperature sensitive switch that is closed at
temperatures below 5 °C (41 °F) and open at temperatures of 5 °C (41 °F) and above.

HEATING AND VENTILATION
80-10DESCRIPTION AND OPERATION
FBH unit
1Air inlet hose
2Electrical connectors
3Exhaust pipe
4Quick disconnect coupling5Coolant inlet hose
6Fuel supply line
7Circulation pump
8Coolant outlet hose
The FBH unit is installed on the bulkhead in the engine compartment, on the side opposite the brake servo, and is
connected in series in the coolant supply to the heater assembly. Two electrical connectors on the top of the FBH unit
connect to the vehicle wiring.
FBH unit connector pin details
Connector/Pin
No.Description Input/Output
C0925
2 K line (diagnostics) Input/Output
3 Alternator power supply Input
6 FBH fuel pump Output
C0926
1 Battery power supply Input
2Earth -

HEATING AND VENTILATION
DESCRIPTION AND OPERATION 80-13
Operation
Air distribution
Turning the distribution knob on the control panel turns the control flaps in the heater assembly to direct air to the
corresponding fascia and footwell outlets.
Air temperature
Turning the LH or RH temperature knob on the control panel turns the related blend flaps in the heater assembly. The
blend flaps vary the proportion of air going through the cold air bypass and the heater matrix. The proportion varies,
between full bypass no heat and no bypass full heat, to correspond with the position of the temperature knob.
Blower speed
The blower can be selected off or to run at one of four speeds. While the ignition is on, when the blower switch is set
to positions 1, 2, 3, or 4, ignition power energises the blower relay, which supplies battery power to the blower. At
switch positions 1, 2 and 3, the blower switch also connects the blower to different earth paths through the resistor
pack, to produce corresponding differences of blower operating voltage and speed. At position 4, the blower switch
connects an earth direct to the blower, bypassing the resistor pack, and full battery voltage drives the blower at
maximum speed.
Fresh/Recirculated inlet air
When the recirculated air switch is latched in, the amber indicator LED in the switch illuminates and an earth is
connected to the recirculated air side of the fresh/recirculated air servo motor. The fresh/recirculated air servo motor
then turns the control flaps in the air inlet duct to close the fresh air inlet and open the recirculated air inlets.
When the latch of the recirculated air switch is released, the amber indicator LED in the switch extinguishes and the
earth is switched from the recirculated air side to the fresh air side of the fresh/recirculated air servo motor. The fresh/
recirculated air servo motor then turns the control flaps in the air inlet duct to open the fresh air inlet and close the
recirculated air inlets.
FBH system (where fitted)
The FBH system operates only while the engine is running and the ambient temperature is less than 5 °C (41 °F).
With the engine running and the ambient temperature below 5 °C (41 °F), the air temperature sensor connects the
alternator power supply to the ECU in the FBH unit. On receipt of the alternator power supply, the ECU starts the
circulation pump and, depending on the input from the temperature sensor in the heat exchanger, enters either a
standby or active mode of operation. If the heat exchanger casing temperature is 65 °C (149 °F) or above, the ECU
enters a standby mode of operation. If the heat exchanger casing temperature is below 65 °C (149 °F), the ECU enters
an active mode of operation. In the standby mode, the ECU monitors the heat exchanger casing temperature and
enters the active mode if it drops below 65 °C (149 °F). In the active mode, the ECU initiates a start sequence and
then operates the system at full or part load combustion to provide the required heat input to the coolant.
Start sequence
At the beginning of the start sequence the ECU energises the glow plug function of the glow plug/flame sensor, to
preheat the combustion chamber, and starts the combustion air fan at slow speed. After 30 seconds, the ECU
energises the FBH fuel pump at the starting sequence speed. The fuel delivered by the FBH fuel pump evaporates in
the combustion chamber, mixes with air from the combustion air fan and is ignited by the glow plug/flame sensor. The
ECU then progressively increases the speed of the FBH fuel pump and the combustion air fan to either part or full
load speed, as required by the system. Once full or part load speed is achieved, the ECU switches the glow plug/flame
sensor from the glow plug function to the flame sensing function to monitor combustion. From the beginning of the
start sequence to stable combustion takes approximately 90 seconds for a start to part load combustion and 150
seconds for a start to full load combustion.

HEATING AND VENTILATION
80-14DESCRIPTION AND OPERATION
Coolant temperature control
When the ECU first enters the active mode, it initiates a start to full load combustion. Full load combustion continues
until the heat exchanger casing temperature reaches 60 °C (140 °F), when the ECU decreases the speed of the FBH
fuel pump and the combustion air fan to half speed, to produce part load combustion. The ECU maintains part load
combustion while the heat exchanger casing temperature remains between 54 and 65 °C (129 and 149 °F). If the heat
exchanger casing temperature decreases to 54 °C (129 °F), the ECU switches the system to full load combustion
again. If the heat exchanger casing temperature increases to 65 °C (149 °F), the ECU enters a control idle phase of
operation.
On entering the control idle phase, the ECU immediately switches the FBH fuel pump off, to stop combustion, and
starts a timer for the combustion air fan. After a 2 minute cooldown period, the ECU switches the combustion air fan
off and then remains in the control idle phase while the heat exchanger casing temperature remains above 59 °C (138
°F). If the heat exchanger casing temperature decreases to 59 °C (138 °F), within 15 minutes of the ECU entering the
control idle phase, the ECU initiates a start to part load combustion. If more than 15 minutes elapse before the heat
exchanger casing temperature decreases to 59 °C (138 °F), the ECU initiates a start to full load combustion.
In order to limit the build-up of carbon deposits on the glow plug/flame sensor, the ECU also enters the control idle
phase if the continuous part and/or full load combustion time exceeds 72 minutes. After the cooldown period, if the
heat exchanger casing is still in the temperature range that requires additional heat, the ECU initiates an immediate
restart to part or full load combustion, as appropriate.
Shutdown
The FBH system is de-activated when the alternator power supply to the FBH unit is disconnected, either by the
engine stopping or, if the ambient temperature increases to 5 °C (41 °F) or above, by the contacts in the air
temperature sensor opening. If the system is active when the alternator power supply is disconnected, the ECU de-
energises the FBH fuel pump to stop combustion, but continues operation of the combustion air fan and the circulation
pump to cool down the FBH unit. The cool down time depends on the combustion load at the time the alternator power
input is disconnected.
Cool down times
Diagnostics
The ECU in the FBH unit monitors the system for faults. Any faults detected are stored in a volatile memory in the the
ECU, which can be interrogated by Testbook. A maximum of three faults and associated freeze frame data can be
stored at any one time. If a further fault is detected, the oldest fault is overwritten by the new fault.
The ECU also incorporates an error lockout mode of operation that inhibits system operation to prevent serious faults
from causing further damage to the system. In the error lockout mode, the ECU immediately stops the FBH fuel pump,
and stops the combustion air fan and circulation pump after a cool down time of approximately 2 minutes. Error lockout
occurs for start sequence failures and/or combustion flameouts, heat exchanger casing overheat and out of limit input
voltage. The error lockout mode can be cleared using Testbook, or by disconnecting the battery power supply for a
minimum of 10 seconds.
Start failure/flameout. If a start sequence fails to establish combustion, or a flameout occurs after combustion is
established, the ECU immediately initiates another start sequence. The start failure or flameout is also recorded by
an event timer in the ECU. The event timer is increased by one after each start failure or flameout, and decreased by
one if a subsequent start is successful. If the event timer increases to three (over any number of drive cycles), the
ECU enters the error lockout mode.
Heat exchanger casing overheat. To protect the system from excessive temperatures, the ECU enters the error
lockout mode if the heat exchanger casing temperature exceeds 105 °C (221 °F).
Out of limit voltage. The ECU enters the error lockout mode if the battery or alternator power input is less than 10.5 ±
0.3 V for more than 20 seconds, or more than 15.5 ± 0.5 V for more than 6 seconds.
Combustion load Cool down time, seconds
Part 100
Full 175

CHARGING AND STARTING
REPAIRS 86-1-1
CHARGING AND STARTING REPAIRS
Alternator - diesel
$% 86.10.02
Remove
1.Remove auxiliary drive belt.

+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
2.Release cover and remove nut securing lead
to alternator.
3.Disconnect alternator multiplug.
4.Remove bolt (LH thread) and remove auxiliary
drive belt tensioner. 5.Remove bolt securing support stay to
alternator.
6.Release clip and disconnect oil drain hose from
vacuum pump.
7.Disconnect vacuum pump oil supply pipe from
cylinder head and discard 'O' ring.
8.Remove bolt securing alternator and release
from mounting bracket.
9.Disconnect vacuum hose from vacuum pump.
10.Remove alternator. Take care not to damage
radiator cooling fins.
11.Remove 4 bolts, and remove vacuum pump
from alternator.
CAUTION: Always fit plugs to open
connections to prevent contamination.

CHARGING AND STARTING
86-1-2 REPAIRS
Refit
1.Clean mating faces of alternator and vacuum
pump.
2.Fit vacuum pump to alternator and tighten
bolts to 8 Nm (6 lbf.ft).
3.Position alternator to engine and connect
multiplug.
4.Connect vacuum hose and oil drain hose to
vacuum pump and secure clips.
5.With assistance align alternator to mounting
bracket and fit but do not tighten bolt.
6.Fit bolt securing support stay to alternator and
tighten to 25 Nm (18 lbf.ft) .
7.Tighten bolt securing alternator to mounting
bracket to 45 Nm (33 lbf.ft).
8.Using new 'O' ring, connect oil supply pipe to
cylinder head and tighten to 10 Nm (7 lbf.ft).
9.Connect lead to alternator and tighten nut to 6
Nm (4.4 lbf.ft).
10.Fit auxiliary drive belt tensioner and tighten bolt
to 50 Nm (37 lbf.ft).
11.Fit auxiliary drive belt.

+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.

CHARGING AND STARTING
REPAIRS 86-1-3
Alternator - V8
$% 86.10.02
Remove
1.Remove auxiliary drive belt.

+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
2.Remove 2 bolts securing alternator to
mounting bracket.
3.Release alternator from mounting bracket
4.Remove nuts securing alternator cables, and
release cables. 5.Remove alternator from mounting bracket.
6.Remove pulley from alternator.
Refit
1.Fit alternator pulley and tighten nut to 80 Nm
(59 lbf.ft).
2.Position alternator to mounting bracket.
3.Connect alternator cables and tighten B+ nut to
18 Nm (13 lbf.ft), and D+ nut to 5 Nm (3.7 lbf.ft).
4.Locate alternator in mounting bracket.
5.Fit alternator mounting bolts and tighten to 45
Nm (33 lbf.ft).
6.Fit auxiliary drive belt.

+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.