1995 LAND ROVER DISCOVERY air condition

AIR CONDITIONING
1
SPECIFICATIONS, TORQUE TORQUE VALUES
NOTE: Torque wrenches should be regularly checked for accuracy to ensure that all fixings are
tightened to the correct torque.
Nm
Air conditioning
Compressor flange bolts 10............................................................................
Receiver drier union bolts 6...........................................................................
Dual pressure switch 11..................................................................................
Pressure pipe union nuts - M16 14.................................................................
Discharge pipe union nuts - M22 22...............................................................
Suction pipe union nuts - M24 33...................................................................
AIR CONDITIONING CHARGE DATA
Total oil in system 180ml - 6.3Fl oz...........................................................................
Total refrigerant in system 0,90kg - 32Fl oz..............................................................
Total refrigerant in system with rear air conditioning 1,15kg - 40Fl oz.......................

ELECTRICAL
1
DESCRIPTION AND OPERATION ELECTRICAL EQUIPMENT
DESCRIPTION
The electrical system is Negative ground, and it is
most important to ensure correct polarity of the
electrical connections at all times. Any incorrect
connections made when reconnecting cables may
cause irreparable damage to the semi-conductor
devices used in the generator and regulator. Incorrect
polarity would also seriously damage any
transistorized equipment such as radio and
tachometer etc.
WARNING: During battery removal or
before carrying out any repairs or
maintenance to electrical components
always disconnect the battery negative lead first.
If the positive lead is disconnected with the
negative lead in place, accidental contact of the
wrench to any grounded metal part could cause a
severe spark, possibly resulting in personal
injury. Upon installation of the battery the positive
lead should be connected first.
GENERATOR
The generator is a three phase, field sensed unit. The
rotor and stator windings produce three phase
alternating current, AC, which is rectified to direct
current, DC. The electronic voltage regulator unit
controls the generator output voltage by high
frequency switching of the rotor field circuit. Use only
the correct Vehicle replacement fan belt. Occasionally
check that the engine and generator pulleys are
accurately aligned.
It is essential that good electrical connections are
maintained at all times. Of particular importance are
those in the charging circuit (including those at the
battery) which should be occasionally inspected to
see that they are clean and tight. In this way any
significant increase in circuit resistance can be
prevented.Do not disconnect battery cables while the engine is
running or damage to the semi-conductor devices
may occur. It is also inadvisable to break or make any
connections in the generator charging and control
circuits while the engine is running.
The electronic voltage regulator employs micro-circuit
techniques resulting in improved performance under
difficult service conditions. The whole assembly is
encapsulated in silicone rubber and housed in an
aluminium heat sink, ensuring complete protection
against the adverse effects of temperature, dust, and
moisture etc.
The regulating voltage is set during manufacture to
give the required regulating voltage range of 14.2±
0.2 volts, and no adjustment is necessary. The only
maintenance needed is the occasional check on
terminal connections and wiping with a clean dry
cloth.
The generator system provides for direct connection
of a charge (ignition) indicator warning light, and
eliminates the need for a field switching relay or
warning light control unit. As the warning lamp is
connected in the charging circuit, lamp failure will
cause loss of charge. Lamp should be checked
regularly and spare carried.
When using rapid charge equipment to re-charge the
battery, the battery must be disconnected from the
vehicle.
NOTE: For description and operation of
electrical circuits see separate publication:
Electrical Troubleshooting Manual.

ELECTRICAL
3
DESCRIPTION AND OPERATION Radio frequency system
The RF system uses four frequencies according to
market. If the coaxial aerial is not fitted system
performance will be impaired. Both ECU and handset
have a colour coded label.
Frequency Colour Territory
ECU/Handset
433.92 MHz Blue/black........................... UK, Ireland........................
224.5 MHz, Yellow/yellow............................ France...................
433.92 MHz Blue/Purple........................... Germany......................
433.92 MHz Blue/blue........................... Europe, not France, Switzerland, Italy, Denmark,..........................
Germany
433.92 MHz White/Blue........................... Switzerland, Denmark.......................
315.0 MHz Green/green............................. Rest of world, Italy, Australia....................
315.0 MHz Orange/Green............................. Gulf, Japan..................
Partially armed mode
If a door, tailgate or bonnet [hood] is left open when
the system is armed, the LED will not light for 10
seconds indicating a mislock condition. Hazard lights
will not flash. If an open door or tailgate is causing the
mislock, the starter motor is disabled. The alarm will
sound if ignition is turned to start position. If an open
bonnet [hood] is causing the mislock the starter motor
is disabled. The alarm will arm the volumetric part of
the system. If the door tailgate or bonnet [hood] is
subsequently closed, after a 5 second delay, the
doors will unlock and immediately lock and the system
will fully arm.
Handset transmitter
The handset LED will give one short flash when
button is pressed momentarily.
If button is held down the LED will light again after 2
seconds for 2 seconds, and extinguish until button is
released and repressed. The handset contains unique
information distinguishing it from other transmitters. It
also contains a set of 'random' rolling codes
programmed into the ECU before leaving the factory.
Each time the handset is pressed a different code is
transmitted to the ECU.
If handset is operated more than four times outside
the vehicle range (6 metres) or power supply is
removed, it will be necessary to re-sychronise handset
and the ECU by pressing the handset three times
within range and within 5 seconds.
NOTE: If both handsets are lost or
damaged when system is armed it will be
necessary to fit a new ECU with two
matching handsets.
Handset batteries
If handset LED flashes continuously when button is
pressed, the batteries need replacing. The hazard
lights will flash one 3 second pulse, instead of three
times upon arming vehicle.
Power up mode
The alarm system always remembers the state it was
left in when power was removed. If the alarm powers
up in an armed state and is subsequently triggered it
will give a warning that it will fully trigger unless
disarmed. This warning consists of short horn pulses
every two seconds for 15 seconds.
New born mode
When the ECU is first produced, it will be in its 'new
born' mode. In this mode it will respond to any remote
of the right frequency. This mode will be cancelled
when the ECU has received ten valid handset signals
without power interruption.
Engine cranking
It is only possible to crank the engine when ignition is
ON and alarm disabled.

86ELECTRICAL
8
DESCRIPTION AND OPERATION DETECTION COMPONENTS
Switches
Perimetric protection for the vehicle is provided by
ECU inputs connected to the following:
Key switches (including starter)
Sill buttons
Bonnet switch
Door switches
Ultrasonic sensor
The ultrasonic sensor is located on the interior light
switch panel and triggers the alarm if movement is
detected.
WARNING INDICATORS
Battery backed-up sounder
The battery backed-up sounder is located in the
engine compartment and provides an audible warning
whenever the alarm is triggered.
NOTE: Disconnecting the vehicle battery
will result in the alarm sounding if the
correct procedure has not been followed.
See Repair, Battery.
Engine immobilisation warning light (EIWL)
The engine immobilisation warning light is located in
the instrument pack and provides a visual indication
that the engine is immobilised.
Anti-theft alarm indicator light
The anti-theft alarm indicator light is located in the
instrument pack and provides a visual indication of the
alarm status.
Inertia switch and central door locking
As a safety feature, the alarm system is designed to
recognise the inertia switch and via the ECU, unlock
the doors in the event of a collision.
NOTE: This feature only applies when the
starter switch is in the on position.ANTI-THEFT ALARM OPERATION (96 MODELS)
Full arming and immobilisation
Locking the vehicle using the handset immobilises the
engine and initializes both volumetric and perimetric
protection, providing:
1.After a lock signal has been received, a period of
15 seconds has elapsed during which no
movement is detected inside the vehicle;
2.No door or bonnet is open.
NOTE: If either of the above conditions are
not satisfied, the alarm will only be
partially armed. This is a mislock condition
which will be made apparent by a delay of 10
seconds before the anti-theft alarm indicator
begins to flash.
Disarming the alarm
NOTE: ALWAYS disarm the alarm using
the handset.
Unlocking with the key will not disarm the alarm or
mobilise the vehicle. If the handset fails to unlock the
vehicle
See Repair, Handset.
Partial arming and immobilisation
The alarm will be partially armed and the engine
immobilised if the vehicle is locked with the handset or
key, if:
1.After a lock signal has been received, a period of
15 seconds has elapsed during which movement
is detected inside the vehicle;
2.A door or bonnet is open.
NOTE: This is a mislock condition which
will be made apparent by a delay of 10
seconds before the anti-theft alarm
indicator begins to flash. Subsequent closure of
the offending aperture will cause the alarm to
attempt full arming as previously described.
Immobilisation
The vehicle will be automatically immobilised
whenever any of the following conditions occur:
1.The vehicle is locked using the handset.
2.The vehicle is locked using the key.
3.Thirty seconds after the starter switch has been
turned off AND the driver's door opened.
4.Five minutes after the starter switch is turned off
or the alarm disarmed.

ELECTRICAL
9
DESCRIPTION AND OPERATION Mobilisation
The vehicle can be mobilised using any one of the
following processes:
1.Placing the handset in close proximity to the
starter switch with the starter switch turned on
(normally achieved by placing the key in the
starter switch, providing the key and handset are
attached).
NOTE: Under normal circumstances the
remobilisation of the vehicle will not be
apparent.
2.Pressing unlock button on handset.
3.Pressing lock button on handset with starter
switch turned on.
4.Entry of EKA code using the key.
NOTE: Any attempt to start the vehicle
using the key (detached from the handset)
will be unsuccessful. Use one of the above
methods.
See Warning indicators.
Volumetric protection
When the vehicle is locked using the handset both
perimetric and volumetric protection are activated
providing there is no mislock condition.
Perimetric protection
The vehicle is always perimetrically protected when
the alarm is armed using the handset. Perimetric
protection only, can be achieved if the vehicle is
locked using the key.
NOTE: The handset should ALWAYS be
used for unlocking the vehicle. If the
handset fails to unlock the vehicle
See
Repair, Handset.
Battery backed-up sounder (BBUS)
The sounder provides audible indication of alarm
status including:
Anti-theft warnings;
Confirmation of access to built-in test.
NOTE: Disconnecting the vehicle battery
will result in the alarm sounding if the
correct procedure has not been followed.
See Repair, Battery.
Alarm horn
The horn provides audible indication (as BBUS) of
alarm status.
NOTE: Disconnecting the vehicle battery
will have no effect on the horn.
Engine immobilisation warning light (EIWL)
NOTE: Under normal circumstances the
light will not illuminate.
The light will only illuminate (after 2 seconds) if the
handset is detached from the key (or the handset
fails) and an attempt is made to start the vehicle.
Anti-theft alarm indicator light
The light flashes to indicate the alarm status.
If the alarm system is fully armed, the light will flash
rapidly for 10 seconds and then settle to the slow
(anti-theft deterrent) flash.
If the alarm system is perimetrically armed, the light
will intermittently flash rapidly for 10 seconds and then
settle to the slow (anti-theft deterrent) flash.
If the alarm system is partially armed, the light will
NOT emit the slow flash until 10 seconds after arming
(to allow the cause to be investigated).
If the vehicle has been left unlocked, providing the
driver's door is closed, the light will flash slowly
indicating immobilisation. If the driver's door is open,
the light will remain illuminated.
Emergency key access (EKA)
The emergency key access code should be entered in
accordance with the instructions in the Owner's
Handbook.

ELECTRICAL
1
FAULT DIAGNOSIS GENERAL INFORMATION
The electrical fault diagnostic tool on Discovery
vehicles is Testbook. Detailed information of electrical
systems, component locations and circuit diagrams
are covered in the Discovery Electrical
Troubleshooting Manual.
See INTRODUCTION,
Information, Fault Diagnostic Equipment
This section covers checks of the charging and
ignition system.
GENERATOR TESTING
Service repair no - 86.10.01
Charging system check
1.Check battery is in good condition, with an open
circuit voltage of at least 12.6 V. Recharge or
substitute battery to carry out test.
2.Check drive belt condition.
See SECTION 10,
Maintenance, Under Bonnet [Hood]
Maintenance
3.Check battery connections are clean and tight.
4.Check generator connections are clean and
tight.
5.Ensure there is no drain on battery from, for
example, interior, under bonnet [hood] or door
edge lamps.
Generator test
Following instructions refer to use of suitable test
equipment using a carbon pile rheostat.
6.Connect test equipment referring to
manufacturer's instructions.
7.Start engine and run at 3000 rev/min without
accessory load.
8.Rotate carbon pile load control to achieve
greatest output (amps) without allowing voltage
to fall below 12.0 V. A reading in amps, of
generator output, minus 10% to allow for EFI
and Ignition loss, should be obtained.
9.Run engine at 3000 rev/min, switch selector to
regulator test, read voltmeter. A reading of 13.6
to 14.4 V should be obtained.
10.Switch selector to diode/stator test, switch on
headlamps to load generator. Raise engine
speed to 3000 rev/min, read voltmeter, needle
must be within 'OK' range.TESTING IN POSITION
Charging circuit resistance test.
1.Connect a low range voltmeter between
generator terminal marked B+ and positive
terminal of battery.2.Switch on headlamps, start engine. Run engine
at approximately 3000 rev/min. Note voltmeter
reading.
3.Transfer voltmeter connections to frame of
generator and negative terminal of battery, and
again note voltmeter reading.
4.If reading exceeds 0.5 volt on positive side or
0.25 volt on negative side, there is a high
resistance in charging circuit which must be
traced and remedied.

86ELECTRICAL
2
FAULT DIAGNOSIS LUCAS CONSTANT ENERGY IGNITION SYSTEM -
V8i
Preliminary checks
Inspect battery cables and connections to ensure they
are clean and tight. Check electrical condition of
battery.
Inspect all L.T. connections, ensure they are clean
and tight. Check H.T. leads are correctly positioned
and not shorting to ground against any engine
components. Wiring harness and individual cables
should be firmly fastened to prevent chaffing.
Pick-up air gap
Check air gap between pick-up limb and reluctor teeth
is 0.20 - 0.35 mm, using a non-ferrous gauge.
NOTE: Air gap is set initially at factory and
will only require adjusting if tampered with
or when pick-up module is replaced.
TEST 1:
H.T. Sparking
Remove coil/distributor H.T. lead from distributor
cover and hold approximately 6mm from engine block,
using suitable insulated pliers. Switch ignition 'On' and
operate starter.
Regular sparking indicates fault in H.T. distribution,
plugs, timing or fuelling, proceed to Test 6. If no spark
or weak spark occurs proceed to Test 2.TEST 2:
L.T. Voltage
Switch ignition 'On' - engine stationary.
(a) Connect voltmeter to points in circuit indicated
by V1 to V4 and make a note of voltage
readings.
(b) Compare voltages obtained with specified
values listed below:
Expected readings
V1 More than 12 volts.
V2 1 volt maximum below volts at V1.
V3 1 volt maximum below volts at V1.
V4 0 volt - 0.1 volt.
(c) If all readings are correct proceed to Test 3.
(d) Check incorrect reading(s) with chart to identify
area of possible faults, i.e. faults listed under
heading SUSPECT and rectify.
(e) If coil and amplifier is suspected, disconnect L.T.
lead at coil, repeat V3. If voltage is still incorrect,
fit new coil. If voltage is now correct, check L.T.
lead, if satisfactory fit new amplifier.
(f) If engine will not start proceed to Test 3.

ELECTRICAL
1
ADJUSTMENT IGNITION TIMING
Service repair no - 86.35.15
Adjust
1.It is essential that following procedures are
adhered to. Inaccurate timing can lead to serious
engine damage and additionally create failure to
comply with emission regulations. If timing is
being checked in vehicle, air conditioning
compressor must be disengaged.
2.On initial engine build, or if distributor has been
disturbed for any reason, ignition timing must be
set statically to 6°B.T.D.C.
NOTE: This approximate setting is made
only to ensure that engine may be started.
CAUTION: On no account must engine be
started before this operation is carried out.Equipment required :-
Calibrated Tachometer
Stroboscopic lamp
3.Couple stroboscopic timing lamp and tachometer
to engine following manufacturer's instructions.
4.Disconnect vacuum hose from distributor.
5.Start engine. With no load, and without
exceeding 3,000 rev/min run engine until normal
operating temperature is reached. (Thermostat
open). Check that engine idles within tolerance
specified in data section.
6.Idle speed for timing purposes must not exceed
800 rev/min.
7.Run engine at idle speed and check timing using
stroboscope light on timing marker and pointer.
WARNING: Keep hands and equipment
away from belt.
8.If timing is not as specified, switch off engine.
Loosen distributor clamp bolt and turn distributor
to advance or retard ignition as necessary.
Tighten clamp bolt, start engine and recheck
timing.
WARNING: Personal injury may result if an
attempt is made to adjust distributor whilst
engine is running.
9.Upon completion, switch off engine and retighten
distributor clamping bolt securely. Recheck
timing, to ensure retightening has not disturbed
distributor position.
10.Refit vacuum hose.
11.Disconnect stroboscopic timing lamp and
tachometer from engine.