maintenance LAND ROVER DISCOVERY 1995 Service Manual

82AIR CONDITIONING
8
REPAIR HEATER AND COOLER UNIT
Service repair no - 86.25.21
WARNING: All work involving the service
and maintenance of air conditioning
requires special equipment, knowledge,
experience and a full awareness and adherence to
safety precautions.
Remove
1.Disconnect battery negative lead.
2.Drain engine coolant.
See COOLING SYSTEM,
Adjustment, Coolant
3.Recover refrigerant from air conditioning system.
See Adjustment, Refrigerant Recovery
Recycling Recharging
4.Remove fascia panel assembly.See CHASSIS
AND BODY, Repair, Dash Panel Assembly
5.Release clips and disconnect coolant hoses
from heater pipes.
6.Remove securing bolt and disconnect low
pressure pipe from evaporator.
WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant. Plug all exposed
connections immediately.
7.Release 'P' clip retaining high and low pressure
pipes.
8.Remove securing bolt and disconnect high
pressure pipe from evaporator.
9.Discard 'O' ring seals.

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
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.

ELECTRICAL
3
REPAIR BATTERY
Service repair no - 86.15.01
NOTE: Some vehicles are fitted with a
battery backed-up sounder. Disconnecting
the vehicle battery will cause the alarm to
sound unless the following procedure is followed:
1.Turn starter switch 'ON' then 'OFF'.
2.Disconnect battery WITHIN 15 SECONDS (see
WARNING).
If alarm is accidentally activated, ensure sounder is
connected and silence by turning the starter switch to
position II.
Remove
WARNING: During battery removal or
before carrying out any repairs or
maintenance to electrical components
always disconnect battery negative lead first. If
positive lead is disconnected with negative lead in
place, accidental contact of wrench to any
grounded metal part could cause a severe spark,
possibly resulting in personal injury. Upon
installation of battery connect positive lead first.
3.Disconnect both battery leads, negative first.
4.Release four nuts securing battery bracket in
position.
5.Remove bracket.
6.Remove battery.
Refit
7.Reverse removal procedure.
NOTE: Coat battery clamps and terminals
with petroleum jelly before refitting.DISTRIBUTOR-LUCAS 35 DLM8 - V8i
Service parts
1. Cap
2. HT brush and spring
3. Rotor arm
4. Insulation cover
5. Pick-up module and base plate assembly
6. Vacuum unit
7. Amplifier module
8. 'O'-ring oil seal
9. Gasket