Ford Falcon. Manual — part 309

412-03-9 Air

Conditioning 412-03-9

DESCRIPTION AND OPERATION (Continued)

been a 2 minute delay since engagement +

A/C Pressure Cut-Off Switch (Pressure

evaporator thermistor registers less than 10ºC +

Transducer)

there are no engine/transmission cooling

requirements for high speed fan.)
The condenser fan is also engaged automatically

if there are engine/transmission cooling

requirements, even if the A/C switch is off.
In both low and high speeds, both condenser fans

operate together.

Quick Joint Connection

The A/C pressure transducer is used to interrupt A/C

compressor operation in the event of high or low

system discharge pressures.

The A/C pressure cut-off switch is mounted on the

high pressure discharge hose assembly.

CAUTION: It is necessary to discharge the

refrigerant system to remove the A/C pressure

cut-off switch.

Item

Description

If the compressor discharge pressure drops below

Male fitting

200kPa, the pressure transducer sends a signal

to the EEC which disengages the A/C

O-ring, suction

compression.

Female fitting

If the compressor discharge pressure rises to

Quick joint clamp

approximately 3,170kPa, the pressure transducer

The quick joint connection is a refrigerant line

sends a signal to the EEC which disengages the

coupling held together with a plastic clamp. The

A/C compressor.

plastic clamp has locking tabs that grip the tube shape

When the pressure drops to approximately

and hold tubes together.

2,570kPa, the pressure transducer signal via the

The o-ring seals are black in colour and made of

EEC allows the A/C compressor to re-engage.

a special material compatible with refrigerant &

The pressure transducer is also used for condenser

refrigerant oil. Use only black refrigerant O-Rings

fan control.

in this location.

When the A/C switch is engaged below a set

A special service tool is required to remove the

vehicle speed, the condenser fan is engaged

quick joint connector. Its insertion is important to

automatically if the compressor discharge

proper removal of the quick joint.

pressure is high.

Male fitting (suction hose) must be fully inserted

When the compressor discharge pressure

into female fitting.

reaches approximately 2,100kPa, the pressure

Lubricate o-rings with refrigerant oil to make

transducer signal via the EEC engages the

smooth insertion.

high-speed fan control.
When the pressure drops to approximately 1800

kPa, the pressure transducer signal via the EEC

engages the low speed fan control. (If there has

G73302 en

412-03-10 Air

Conditioning 412-03-10

DESCRIPTION AND OPERATION (Continued)

Item

Description

Item

Description

Female fitting

Clamp interlocking tabs

Male fitting

Stopper lever

O-Ring seals

Quick joint clamp removal tool

Clamp guide

Quick joint clamp wraps around the tube

connection.

Air Conditioning Joint Design

Interlocking tabs on clamp hold clamp in place.

In the A/C system, there are 3 types of joints:

Quick joint clamp clicks shut.

radial seal pad fitting or nut joint
Compression seal 45

° taper joint

Radial seal quick connect joint

For all radial seal joints, the O-ring is retained in a

recessed groove. The O-ring seals against leakage

using radial compression once the joint is fully

assembled, and further tightening of the fitting bolt or

tube nut will not improve the sealing performance. Full

insertion of the tube joint is critical to prevent O-ring

damage. All retained O-rings are black refrigerant

O-rings made from a special material compatible with

refrigerant and refrigerant oil. All quick-connect joints

use two black retained refrigerant O-rings for sealing.
At the evaporator inlet and outlet tube joints,

green/blue refrigerant O-rings are used in a 45

° taper

If gap exists, clamp cannot be closed.

compression seal. Again, these O-rings are made of a

Clamp can rotate freely on tube joint until A/C

special material compatible with refrigerant and

system is charged with refrigerant.

refrigerant oil, and are different dimensions to the

Alignment of clamp guide to quick joint clamp

black refrigerant O-rings. In addition, the evaporator

removal tool is required for clamp removal.

tube green/blue refrigerant O-rings are different

dimensions from previous models.
Prior to making any hose/tube connections, lubricate

the O-ring with compressor oil to avoid refrigerant

leakage.
Fine fibre and dust can affect seal performance.

When disassembling joints, keep O-rings capped to

prevent O-ring damage, contamination and moisture

ingression.

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412-03-11 Air

Conditioning 412-03-11

DESCRIPTION AND OPERATION (Continued)

The fitting is an integral part of the refrigeration line or

component.

Special couplings are required for both the

high-side and low-side charge ports.
The Schraeder-type valve core can be replaced if

the seal leaks.
Always install the appropriate A/C charging valve

cap on the charge port valves after repairing the

refrigerant system.
The high pressure charge port cap located on the

liquid line charge port is smaller than the low

pressure charge port cap located on the suction

hose/tube.

Engine Cooling Fans (Condenser Fans)

The vehicle is fitted with dual electric cooling fans

mounted in a fan shroud directly behind the radiator

assembly.
These fans are used for both engine cooling and air

conditioning condenser cooling. The fans are

controlled by three relays via the Powertrain Control

Module, and when required, operate at low speed

(1400 rpm) or high speed (2300 rpm) depending on

the engine and A/C cooling demands.
Refer to Wiring section and Engine Cooling section

303-03 for further details.

CAUTION: When the ignition is ON, the fans

may start without warning.

Charge Port Valves

The high-pressure charge port valve is located on the

CAUTION: During service operations ensure

A/C liquid line (condenser to evaporator line).

that the fan is not rotated in a direction opposing

The low-pressure charge port valve is located on the

normal operation (designated by an arrow on the

suction hose or tube assembly.

fan blade), or this may damage the motor. For

more information refer to section 303-03.

Item

Description

A/C charging valve cap (low pressure)

A/C suction hose/tube

Charge port valve

O-ring seal

A/C liquid line

A/C charging valve cap (high pressure)

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412-03-12 Air

Conditioning 412-03-12

DIAGNOSIS AND TESTING

Air Conditioning

Inspection and Verification

In order to correctly diagnose the root cause of the

fault, it is advisable that the technician follow the

following Air Conditioning System Fault Test process.

System fault

System test A

System test B

System test C

System test D

A/C Cooling

A/C System

A/C Fault Symptom

A/C System Performance test or

WDS tester or

fault

Functional

Chart, then

A/C system leak test or

Pinpoint tests

Inspection test,

A/C system noise test, then

then

A/C Functional Inspection Chart

A/C component

Result for Inspection Pass

System Fault for Inspection Fail

A/C system

Good cooling performance from

Refer to A/C Fault Symptom Chart

system

A/C compressor

Engages with A/C on (comp clutch Wiring fault, refer pinpoint test A

centre turns)

ICC fault, refer 413-08.

A/C cooling fault, refer A/C Fault

Symptom Chart.

Compressor drive belt

Does not slip or whip when A/C is

Accessory drive fault, refer 303-05

engaged

A/C discharge hose

Hot to touch with A/C on