4Refitting is the reverse of the removal
procedure.
5Run the engine and check for proper
functioning of the heater (and air conditioning,
if equipped).
Control checks
6The climate-control system uses an all-
electronic control panel that sends digital
information to the climate control computer.
There is little the home mechanic can do to
troubleshoot or test the system. The factory
recommends that diagnosis be performed at a
dealership.
7If there is a problem in just one area of
climate control, put the controls through their
entire range of operation and check the
system responses, i.e. set the controls to
COLD, the fan to low and the temperature to
65° F. In this mode the Manual LED should be
lit and the air conditioning compressor should
engage. Try all of the fan speeds and try the
temperature on HOT, then feel for warm air
coming from the ducts. Note:Between each
try of the different controls, wait 20 seconds or
so for the heater/air conditioning system to
adjust before checking for a response.
8When each control button is pushed two
times, its LED light should go on or off. Renew
the control assembly if any of the warning
lights don’t work.
9On 1988 and 1989 models, if the climate
controls do not respond to any driver input,
check with your Jaguar dealer before
renewing the ECU or control panel. A service
part is available (a resistor, #JLM 1901) that
can be installed at one of the control panel
terminals that may fix the problem without any
other parts being renewed. Instructions are
included with the part.
10Check the vacuum lines to the several
vacuum motors that operate the heater/air
conditioning functions. Look for pinched or
blocked hoses and leaks.11Each of the vacuum “servo motors” in the
system can be checked with a hand-held
vacuum pump (see illustration). Apply vacuum
and watch that the door or control it operates is
working.
12Further diagnosis of the controls or
climate control ECU are best left to a Jaguar
dealership or other qualified repair facility.
13 Air conditioning and heating
system- check and
maintenance
1
Air conditioning system
Warning: The air conditioning
system is under high pressure.
Do not loosen any hose fittings
or remove any components until
the system has been discharged. Air
conditioning refrigerant should be properly
discharged into an EPA-approved
recovery/recycling unit by a dealer service
department or an automotive air
conditioning repair facility. Always wear
eye protection when working near air
conditioning system fittings.
1The following maintenance checks should
be performed on a regular basis to ensure that
the air conditioner continues to operate at
peak efficiency:
a) Inspect the condition of the compressor
drivebelt. If it is worn or deteriorated,
renew it (see Chapter 1).
b) Check the drivebelt tension and, if
necessary, adjust it (see Chapter 1).
c) Inspect the system hoses. Look for
cracks, bubbles, hardening and
deterioration. Inspect the hoses and all
fittings for oil bubbles or seepage. If there
is any evidence of wear, damage or
leakage, renew the hose(s).d) Inspect the condenser fins for leaves,
bugs and any other foreign material that
may have embedded itself in the fins. Use
a “fin comb” or compressed air to remove
debris from the condenser.
e) Make sure the system has the correct
refrigerant charge.
2It’s a good idea to operate the system for
about ten minutes at least once a month. This
is particularly important during the winter
months because long term non-use can
cause hardening, and subsequent failure, of
the seals.
3Leaks in the air conditioning system are
best spotted when the system is brought up
to operating temperature and pressure, by
running the engine with the air conditioning
ON for five minutes. Shut the engine off and
inspect the air conditioning hoses and
connections. Traces of oil usually indicate
refrigerant leaks.
4Because of the complexity of the air
conditioning system and the special
equipment required to effectively work on it,
accurate troubleshooting of the system
should be left to a professional technician.
5If the air conditioning system doesn’t
operate at all, check the fuse panel and the air
conditioning relay (refer to Chapter 12 for
relay locations and testing). See Sections 4, 9
and 12 for electrical checks of heating/air
conditioning system components.
6The most common cause of poor cooling is
simply a low system refrigerant charge. If a
noticeable drop in cool air output occurs, the
following quick check will help you determine
if the refrigerant level is low.
Checking the refrigerant charge
7Warm the engine up to normal operating
temperature.
8Place the air conditioning temperature
selector at the coldest setting and put the
Cooling, heating and air conditioning systems 3•11
3
3261 Jaguar XJ6 12.3b Remove the four screws (three are shown here) holding the
control assembly in the control/radio housing
12.11 Check the operation of the vacuum servo motors; in this
case, vacuum is applied to the servo on the right blower case -
the flapper door (arrowed) should operate
wash system, radio memory and the ABS
main feed and pump circuits.
In-line fuses are located through out the
vehicle depending on the year, make and
model. Consult the wiring diagrams at the end
of this Chapter for further information.
In-line fuses also have a blade terminal
design, which allow fingertip removal and
renewal. If an electrical component fails,
always check the fuse first. A blown fuse is
easily identified through the clear plastic
body. Inspect the element for evidence of
damage (see illustration 3.3).
Be sure to renew blown fuses with the
correct type. Fuses are usually colour-coded
to indicate their rating. Fuses of different
ratings are physically interchangeable, but
only fuses of the proper rating should be
used. Replacing a fuse with one of a different
value than specified is not recommended.
Each electrical circuit needs a specific
amount of protection. The amperage value of
each fuse is moulded into the fuse body.If the renewal fuse immediately fails, don’t
renew it again until the cause of the problem
is isolated and corrected. Don’t substitute
anything else for the fuse. In most cases, this
will be a short circuit in the wiring caused by a
broken or deteriorated wire.
5 Circuit breakers-
general information
Circuit breakers generally protect
components such as electric windows, central
locking and headlights. On some models the
circuit breaker resets itself automatically, so
an electrical overload in the circuit will cause it
to fail momentarily, then come back on. If the
circuit doesn’t come back on, check it
immediately. Once the condition is corrected,
the circuit breaker will resume its normal
function. Some circuit breakers have a button
on top and must be reset manually.To test a circuit breaker, use an ohmmeter
to check continuity between the terminals. A
reading of zero to 1.0 ohms indicates a good
circuit breaker. An open circuit reading on the
meter indicates a bad circuit breaker.
6 Relays- general information
and testing
2
General information
Several electrical accessories in the vehicle,
such as the fuel injection system, electric
windows, central locking, etc, use relays to
transmit the electrical signal to the component.
Relays use a low-current circuit (the control
circuit) to open and close a high-current circuit
(the power circuit). If the relay is defective, that
component will not operate properly. The
relays are mounted throughout the vehicle (see
illustrations). If a faulty relay is suspected, it
Body electrical system 12•3
12
3261 Jaguar XJ6 1988 to 1989 relay location details
3261 Jaguar XJ6
Dimensions and weights . . . . . . . . . . . . . . . . . . .REF•1
Jacking and vehicle support . . . . . . . . . . . . . . . .REF•1
Radio/cassette unit anti-theft system . . . . . . . . .REF•1
Conversion factors . . . . . . . . . . . . . . . . . . . . . . .REF•2
Use of English . . . . . . . . . . . . . . . . . . . . . . . . . . .REF•3
Buying spare parts . . . . . . . . . . . . . . . . . . . . . . . .REF•4
Vehicle identification . . . . . . . . . . . . . . . . . . . . . .REF•4General repair procedures . . . . . . . . . . . . . . . . .REF•5
Tools and working facilities . . . . . . . . . . . . . . . . .REF•6
MOT test checks . . . . . . . . . . . . . . . . . . . . . . . . .REF•8
Fault finding . . . . . . . . . . . . . . . . . . . . . . . . . . . .REF•12
Glossary of technical terms . . . . . . . . . . . . . . . .REF•18
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .REF•22
Dimensions and weights
Note:All figures are approximate, and may vary according to model. Refer to manufacturer’s data for exact figures.
Dimensions
Overall length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4988 mm
Overall width (including mirrors) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2015 mm
Overall height (unladen) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1358 mm
Wheelbase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2870 mm
Weights
Kerb weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1770 kg
Maximum gross vehicle weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2190 kg
Maximum towing weight:
Braked trailer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1500 kg
Unbraked trailer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750 kg
Maximum axle load:
Front axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1050 kg
Rear axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1170 kg
Maximum roof rack load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 kg
ReferenceREF•1
Radio/cassette unit anti-theft system - precaution
Some models are equipped with an audio
system which includes an anti-theft feature, to
deter thieves. If the power source to the unit is
cut, the anti-theft system will activate. Even if
the power source is immediately reconnected,
the radio/cassette unit will not function untilthe correct security code has been entered.
Therefore if you do not know the correct
security code for the unit, do notdisconnect
the battery negative lead, or remove the
radio/cassette unit from the vehicle.The procedure for reprogramming a unit
that has been disconnected from its power
supply varies from model to model - consult
the handbook supplied with the unit for
specific details or refer to your Jaguar dealer. The jack supplied with the vehicle tool kit
should only be used for changing the
roadwheels - see “Wheel changing”at the
front of this manual. When carrying out any
other kind of work, raise the vehicle using a
hydraulic (or “trolley”) jack, and always
supplement the jack with axle stands
positioned under the vehicle jacking points.
To raise the front of the vehicle, place a
block of wood on the jack head and positionthe jack underneath the centre of the front
crossmember. Lift the vehicle to the required
height and support it on axle stands
positioned underneath the vehicle jacking
points on the sills.
To raise the rear of the vehicle, place a
block of wood on the jack head and position
the jack underneath the centre of the rear
crossmember. Lift the vehicle to the required
height and support it on axle standspositioned underneath the vehicle jacking
points on the sills.
The jack supplied with the vehicle locates in
the jacking points on the sills. Ensure that the
jack head is correctly engaged before
attempting to raise the vehicle.
Neverwork under, around, or near a raised
vehicle, unless it is adequately supported in at
least two places.
Jacking and vehicle support