Pressure Switch - wsm STW37 Workshop Manual

STW34, STW37, STW40, WSM

(8) Pressure Switch

Functional Check
NOTE
• The relays described here are used same ones so that
these are interchangeable.
1. Apply the battery voltage across the terminal 1 and 2, and check
for continuity across the terminal 3 and 4.
2. If continuity is not established across the terminal 3 and 4,
replace it.
(1) Battery
Pressure Switch
1) HI Pressure Side
1. Connect the manifold gauge (1) to compressor as following
procedure.
Close the HI and LO pressure valves (6), (7) of manifold gauge
tightly, and connect the charging hoses (4), (5) (red and yellow)
to the respective compressor service valves.
NOTE
• Be sure to drive out the air in the charging hoses at the
manifold gauge connection end by utilizing the refrigerant
pressure in the refrigerant cycle.
2. Start the engine and set at approx. 1500 min
the A/C switch, then set the blower switch to HI position.
3. Raise pressure on the HI pressure side of the refrigerant cycle
by covering the condenser front with a corrugated carboard, and
the pressure switch is activated and the compressor magnetic
clutch is turned off. At this time, read the HI pressure gauge of
the manifold gauge. If this pressure reading differs largely with
the setting pressure, replace the pressure switch with a new
one.
Factory
Setting pressure specifica-
tion
2) LO Pressure Side
1. Disconnect 2P connector of pressure switch (8).
2. Measure the resistance with an ohmmeter across the connector
terminals.
3. If 0 ohm is not indicated at normal condition, there is no
refrigerant in the refrigerating cycle because gas leaks or
pressure switch is damaged.
(Reference)
Factory
Setting pressure specifica-
tion
• The resistance of pressure switch is 0 ohm in normal condition,
but it becomes infinity if the pressure is out of factory
specification. Because the pressure switch starts to work.
(1) Manifold Gauge
(2) LO Pressure Side Charging Valve
(3) HI Pressure Side Charging Valve
(4) Charging Hose (Red)
10-S29
(2) Connector (Relay)
9Y1211109CAS0051US0
-1
(rpm). Turn on
More than
Pressure
approx. 3.14 MPa
switch OFF
2
(32 kgf/cm , 455 psi)
Less than
Pressure
approx. 0.196 MPa
switch OFF
2
(2.0 kgf/cm , 28.4 psi)
(5) Charging Hose (Yellow)
(6) HI Pressure Side Valve
(7) LO Pressure Side Valve
(8) Pressure Switch
9Y1211109CAS0047US0
KiSC issued 11, 2014 A
CABIN