82AIR CONDITIONING
6
ADJUSTMENT SYSTEM TEST
1.Place the vehicle in a ventilated, shaded area
free from excessive draught, with the doors and
windows open.
2.Check that the surface of the condenser is not
restricted with dirt, leaves, flies, etc. Do not
neglect to check the surface between the
condenser and the radiator. Clean as necessary.
3.Switch on the ignition and the air conditioner air
flow control. Check that the blower is operating
efficiently at low, medium and high speeds.
Switch off the blower and the ignition.
4.Check that the evaporator condensate drain
tubes are open and clear.
5.Check the tension of the compressor driving belt,
and adjust if necessary.
6.Inspect all connections for the presence of
refrigerant oil. If oil is evident, check for leaks,
and repair as necessary.
NOTE: The compressor oil is soluble in
Refrigerant R134a and is deposited when
the refrigerant evaporates from a leak.
7.Start the engine.
8.Set the temperature controls to cold and switch
the air conditioner blower control on and off
several times, checking that the magnetic clutch
on the compressor engages and releases each
time.
9.With the temperature control at maximum
cooling and the blower control at high speed,
warm up the engine and fast idle at 1000
rev/min.
10.Repeat at 1800 rev/min.
11.Gradually increase the engine speed to the high
range and check the sight glass at intervals.
12.Check for frosting on the service valves.
13.Check the high pressure hoses and connections
by hand for varying temperature. Low
temperature indicates a restriction or blockage at
that point.
14.Switch off the air conditioning blower and stop
the engine.
15.If the air conditioning equipment is still not
satisfactory, carry out a pressure test as
previously described in this section.PRECAUTIONS IN HANDLING REFRIGERANT
LINES
WARNING: Wear eye and hand protection
when disconnecting components
containing refrigerant. Plug all exposed
connections immediately.
1.When disconnecting any hose or pipe
connection the system must be discharged of all
pressure. Proceed cautiously, regardless of
gauge readings. Open connections slowly,
keeping hands and face well clear, so that no
injury occurs if there is liquid in the line. If
pressure is noticed, allow it to bleed off slowly.
2.Lines, flexible end connections and components
must be capped immediately they are opened to
prevent the entrance of moisture and dirt.
3.Any dirt or grease on fittings must be wiped off
with a clean alcohol dampened cloth. Do not use
chlorinated solvents such as trichloroethylene. If
dirt, grease or moisture cannot be removed from
inside the hoses, they must be replaced with
new hoses.
4.All replacement components and flexible end
connections must be sealed, and only opened
immediately prior to making the connection.
5.Ensure the components are at room temperature
before uncapping, to prevent condensation of
moisture from the air that enters.
6.Components must not remain uncapped for
longer than 15 minutes. In the event of delay, the
caps must be fitted.
7.Receiver/driers must never be left uncapped as
they contain Silica Gel crystals which will absorb
moisture from the atmosphere. A receiver/ drier
left uncapped must not be used, fit a new unit.
8.The compressor shaft must not be rotated until
the system is entirely assembled and contains a
charge of refrigerant.
9.A new compressor contains an initial charge of
refrigerant oil. The compressor also contains a
holding charge of gas when received which
should be retained by leaving the seals in place
until the pipes are re-connected.
10.The receiver/drier should be the last component
connected to the system to ensure optimum
dehydration and maximum moisture protection of
the system.
ELECTRICAL
1
REPAIR ELECTRICAL PRECAUTIONS
The following guidelines are intended to ensure the
safety of the operator whilst preventing damage to
electrical and electronic components fitted to the
vehicle.
Polarity
Never reverse connect the vehicle battery and always
observe the correct polarity when connecting test
equipment.
High voltage circuits
WARNING: Before commencing work on
an ignition system, all high tension
terminals, adaptors and diagnostic
equipment for testing should be inspected to
ensure that they are adequately insulated and
shielded to prevent accidental personal contacts
and minimize the risk of shock. Wearers of
surgically implanted pacemaker devices should
not be in close proximity to ignition circuits or
diagnostic equipment.
Whenever disconnecting live high tension circuits
always use insulated pliers and never allow the open
end of a high tension lead to come into contact with
other components particularly electronic control units.
Exercise caution when measuring the voltage on the
coil terminals while the engine is running, since, high
voltage spikes can occur on these terminals.
Connectors and harness
Always ensure that these items are dry and oil free
before disconnecting and connecting test equipment.
Never force connectors apart either by using tools or
by pulling on the wiring harness. Always ensure
locking tabs are disengaged before removal and note
orientation to enable correct reconnection. Ensure that
any protective covers and substances are replaced if
disturbed. Having confirmed a component to be faulty
switch-off the ignition and disconnect the battery.
Remove the component and support the disconnected
harness. When replacing the component keep oily
hands away from electrical connection areas and
push connectors home until any locking tabs fully
engage.Battery disconnecting
Before disconnecting the battery, switch off all
electrical equipment.
Battery charging
Recharge the battery out of the vehicle and keep the
top well ventilated. While being charged or
discharged, and for approximately 15 minutes
afterwards, batteries emit hydrogen gas which is
flammable. Always ensure any battery charging area
is well ventilated and that every precaution is taken to
avoid naked flames and sparks.
GENERAL PRECAUTIONS
Switch-off ignition prior to making any connection or
disconnection in the system as electrical surge
caused by disconnecting 'live' connections can
damage electronic components.
Ensure hands and work surfaces are clean and free of
grease, swarf, etc. as grease collects dirt which can
cause tracking or high-resistance contacts.
When handling printed circuit boards, treat them as
you would a disc - hold by the edges only.
Prior to commencing a test, and periodically during a
test, touch a good earth, for instance, a cigar lighter
socket, to discharge body static as some electronic
components are vulnerable to static electricity.
