DESCRIPTION-Air Conditioner (Manual)
Refrigerant Leak Warning System
The refrigerant leak warning system, used in con-
junction with the low-pressure switch, protects the
cooler cycle from damage due to continued opera-
tion of the
air conditioning system when there is a
shortage of refrigerant
It also indicates when to re-
plenish the refrigerant
Refrigerant leak
warnmg lamp Recirculation switch
Air conditioner switch
control lever
SHA227B
I ll I
SHA2286
When the refrigerant in the cooler cycle is insuffi-
cient,
it vaporizes quickly inside the evaporator As
a result, the "super heat" of the refrigerant at the
outlet of the evaporator increases
If it exceeds the
specified level [Approximately 45°C
(8l0F)1, the
super heat switch turns on, allowing the current to
flow through the timer If current continues to
flow through the timer for the specified length of
time, the timer activates to close the contacts
which turn on the warning lamp
Leak warning lamp check
Conduct a continuity test in the leak warning lamp
circuit.
1) Turn ignition switch "ON" (with engine off) to
make sure warning lamp illuminates.
2) Start engine. Warning lamp should go out if the
amount of refrigerant
is sufficient.
EXPLANATION OF SUPER HEAT
When a liquid under constant pressure inside a
cylinder is heated, it apparently changes in three
different
states The relationship between the tem-
perature of the liquid (refrigerant) and
its volume,
which
uses the pressure as a parameter, is shown in
the graph below.
1) The temperature of the liquid rises along the
saturated liquid line (a -+ b or a + b')
2) When the temperature of the liquid reaches a
certain level, evaporating bubbles quickly ap-
pear This mixture of liquid and vapor contin-
ues to take place, during which the tempera-
ture remains constant until the
last droplet of
liquid vaporizes. Points c and c' where the
entire liquid vaporizes, are located on the
saturated vapor line (b
+ c or b -+ c').
3) When the liquid is further heated, the tempera-
ture of the vapor
rises again and its volume also
increases.
The volume will continue to increase
as the temperature is increased
We call this vapor "super heated vapor" (c + d
or c'
+ d')
The line between points c and c'
is called the
"saturated vapor line."
HA-I 0
A/C ELECTRICAL COMPONENTS (Manual)
Inspection (Cont'd)
Applied voltage to
solenoid (V)
0
1 Disconnect vacuum hose @
2 Disconnect vacuum hose 3 and connect hose
@ instead Suck in through hose @ to con-
firm that
air does not flow through the hose
and that check
valve is closed
While sucking vacuum hose
0, change voltage
to solenoid to check for openclose operation
of solenoid valve
3 ~~
Operation of solenoid
valve
Close
12 1 Open ~ ~~ ~
Pressure
switch check for turbocharged model
I Pressure I Resistance In1 I
Atmospheric
presswe
Vacuum pressure
more than 46 7 kPa 1350 mmHg, 13 78 mHg1
SHAZ55E
1. Disconnect vacuum hose @ from the terminal
and connect
a vacuum handy pump with the
same terminal
2. Check pressure switch using a vacuum handy
pump.
VACUUM PUMP MOTOR
1 Turn ignition switch "OFF" Disconnect
vacuum hose
@ (Refer to "Pressure Switch
Check") from vacuum tank and connect
it
again
2 Make sure air conditioner switch is "OFF"
3 Turn ignition switch "ON" (Do not start the
engine)
4 Push cruise control main switch to make sure
vacuum pump starts. (A sound should
be heard
from the pump
)
5 The vacuum pump is operating properly if it
stops within 20 seconds after it has started
6 If it fails to stop within 20 seconds, and
vacuum hoses are in good order, it is malfunc-
tioning
SOLENOID VALVE
Perlorm operational check, referring to the "Table
of operation of solenoid valve in Air Flow (page
HA-3) and Wiring Diagram (page HA-8 or HA-31)
HA-33
