Removal; Installation; A/C Pressure Transducer; Description - Dodge Dakota Sport 2001 Service Manual

AN
A/C LOSS OF CHARGE SWITCH (Continued)
Also verify that the refrigerant system has the cor-
rect refrigerant charge (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - STANDARD
PROCEDURE).
For circuit descriptions and diagrams, refer to Air
Conditioning/Heater in Wiring Diagrams.
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the loss of charge switch wire harness
connector from the switch on the accumulator fitting.
(3) Install a jumper wire between the two cavities
of the loss of charge switch wire harness connector.
(4) Connect a manifold gauge set to the refrigerant
system service ports (Refer to 24 - HEATING & AIR
CONDITIONING - DESCRIPTION).
(5) Connect the battery negative cable.
(6) Place the heater-A/C mode control switch knob
in any A/C position and start the engine.
(7) Check for continuity between the two terminals
of the low pressure cycling clutch switch. There
should be continuity with a suction pressure reading
of 48–89 kPa (7–13 psi) or above, and no continuity
with a suction pressure reading of 48–89 kPa (7–13
psi) or below. If OK, test and repair the A/C switch
sense circuit as required. If not OK, replace the
faulty switch.

REMOVAL

(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the wire harness connector from the
loss of charge switch on the top of the accumulator.
(3) Unscrew the loss of charge switch from the fit-
ting on the top of the accumulator.
(4) Remove the O-ring seal from the accumulator
fitting and discard.

INSTALLATION

(1) Lubricate a new O-ring seal with clean refrig-
erant oil and install it on the accumulator fitting.
Use only the specified O-rings as they are made of a
special material for the R-134a system. Use only
refrigerant oil of the type recommended for the com-
pressor in the vehicle.
(2) Install and tighten the loss of charge switch on
the accumulator fitting. The switch should be hand-
tightened onto the accumulator fitting.
(3) Plug the wire harness connector into the loss of
charge switch.
(4) Connect the battery negative cable.

A/C PRESSURE TRANSDUCER

DESCRIPTION

This vehicle is equipped with an a/c pressure
transducer. This transducer is screwed onto a fitting
on the liquid line between the condenser and the
high side refrigerant system service port (Fig. 16).
Fig. 16 A/C PRESSURE TRANSDUCER
1 - HIGH SIDE REFRIGERANT SYSTEM SERVICE PORT
2 - LIQUID LINE
3 - A/C PRESSURE TRANSDUCER

OPERATION

The main function of the a/c pressure transducer is
to disengage the compressor clutch when the refrig-
erant system high pressures are too high. The PCM
senses a voltage from the transducer and converts it
to a pressure. Based on this pressure, the PCM will
disengage the clutch at 460 psi and re-engage the
clutch at 290 psi. The a/c heater control also uses the
pressure value to operate the auto-recirculation func-
tion for improved a/c performance under extreme
conditions.
DIAGNOSIS AND TESTING - A/C PRESSURE
TRANSDUCER
Before performing diagnosis of the a/c pressure
transducer switch, verify that the refrigerant system
has the correct refrigerant charge. (Refer to 24 -
HEATING & AIR CONDITIONING - DIAGNOSIS
AND TESTING)
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information in Group 8W).
(1) Turn on engine and have a/c selected.
(2) Using the DRBIII
pressure value as it is sent out from the PCM.
CONTROLS 24 - 17
monitor and record the