Ford Falcon. Manual - part 315

412-03-33 Air 

Conditioning 412-03-33

DIAGNOSIS AND TESTING (Continued)

PINPOINT TEST B : WAC RELAY OPERATION

NOTE: Also refer to PCM section 303-14, Air Conditioner Inputs.

Test Step

Result / Action to Take

B1

CHECK RELAY OPERATION

Turn blower motor to high speed

Yes

Relay operation is normal.

Turn A/C switch on at normal idle condition.

No

Does WAC relay engage.

Go to B2.

B2

CHECK RELAY OPERATION

Set circuit as follows:

Yes

Relay operation is normal. Go to B3

Power (12V) to pin 361 (Pin No.4) on relay
Earth (0V) to pin 321 (Pin No.3) on relay

No

Replace relay.

 

Relay should close to give continuity between circuits 175 (Pin No.2)
and 347 (Pin No.1).

Is the resistance less than 5 Ohms across terminals 1 & 2 ?

B3

CHECK RELAY FOR POWER CIRCUIT 361C

Operate the A/C system at maximum cooling.

Yes

Go to B4

Check voltage between ground and 361C (R) wire on wiring harness.

No

Is voltage greater than 10 Volts?

Repair circuit from EEC to relay and test for
normal operation. Go to B6.

B4

CHECK EEC OUTPUT 321 GRW

Check for resistance between ground and 321 GRW on wiring

Yes

harness.

EEC output is normal. Go to B5.

Is resistance less than 5 Ohms?

No

Check A/C disable strategy chart. Confirm
correct EEC operation. Repair circuit and test for
normal operation.

B5

CHECK WIRING CIRCUIT 347 TO CLUTCH

Check for resistance between circuit 347 at wiring harness and 347 at

Yes

compressor.

Circuit 347 is normal. Go to B6.

Is resistance less than 5 Ohms?

No

Repair circuit and test for normal operation.

B6

CHECK WIRING CIRCUIT 175A FOR POWER

Check voltage between ground and 175A

Yes

Operation is normal.

Is voltage greater than 10 Volts?

No

Repair circuit. Test for normal operation.

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412-03-34 Air 

Conditioning 412-03-34

DIAGNOSIS AND TESTING (Continued)

PINPOINT TEST C : PRESSURE TRANSDUCER OPERATION

NOTE: Also refer to PCM section 303-14, Air Conditioner Inputs.

Test Step

Result / Action to Take

C1

CHECK THE PRESSURE SWITCH REFERENCE

VOLTAGE

Check voltage between ground and circuit 351 BR-W on wiring

Yes

harness.

Go to C2.

Is reference voltage correct to spec: V=5

±0.25V?

No

Repair circuit. Test for normal operation.

C2

CHECK EARTH AT SWITCH

Check resistance between ground and circuit 359 on wiring harness.

Yes

Go to C3.

Is switch earth present?

No

Repair circuit. Test for normal operation.

C3

CHECK SWITCH OUTPUT SIGNAL

Apply 5 V to circuit 351 at switch.

Yes

Switch operation is normal.

Apply earth to circuit 359 at switch.

No

Ensure A/C refrigerant pressure is within 200kPa and 3170 kPa.

REPLACE switch.

Check voltage between ground and circuit 440 at switch.

Is voltage within range 0.0 V to 5.25 V ?

PINPOINT TEST D : EVAPORATOR CORE ICE UP

 CAUTION: Follow all Climate Control system safety precautions when dealing with A/C system

refrigerant.

Test Step

Result / Action to Take

D1

COMPRESSOR CYCLING

Yes

NOTE:

Test can not be conducted in high ambient temperatures, as the

Go to D2.

compressor may not cycle off, if the ambient temperature is high.

No

Turn blower motor to high speed.

Go to PinPoint Test G to check evaporator

Switch A/C ON.

thermistor.

Set to recirculated air.

Set controls to maximum cooling.

Ensure all vehicle doors and windows are closed.

Does the Compressor Cycle OFF and ON?

D2

PRESSURE GAUGE EVALUATION

Yes

Is the suction pressure constantly at or below approx 150 kPa

Conduct A/C Performance test to diagnose the

with the A/C On and Engine speed held at approx 2.000 RPM ?

cause of the Low suction pressure. Refer to
Section 412-03.

No

Go to D3.

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412-03-35 Air 

Conditioning 412-03-35

DIAGNOSIS AND TESTING (Continued)

Test Step

Result / Action to Take

D3

SUCTION TUBE INSPECTION

Yes

Does the Evaporator outlet tube at the Accumulator Frost or

Check Orifice Tube and recharge A/C system for

Ice-up, with the A/C ON, Blower fan speed 1 (low) and the Engine

correct gas charge. Refer to Section 412-03.

speed held at 2000 RPM for 3 - 5 Minutes?

No

Operation is normal.

Special Tool(s)

Evaporator leak test tool

PINPOINT TEST E : EVAPORATOR CORE REFRIGERANT LEAKAGE

 CAUTION: Follow all Climate Control system safety precautions when dealing with A/C system

refrigerant.
NOTE: An Evaporator Core Refrigerant leakage will also cause “Smell”. This is due to the PAG Refrigerant

Oil being released with the Refrigerant.

NOTE: Removal of the Evaporator core should not be undertaken unless all other potential leak sources has

been eliminated.
Prior to removing Evaporator core from the vehicle conduct Fluorescent Dye Leak test and or Electronic Leak

detection (Refer to pg. 412-03-40).

Test Step

Result / Action to Take

E1

VACUUM HOLDING TEST

To attach the Evaporator leak test tool, you must first remove the

Yes

evaporator core. Refer to procedure in this chapter.

Go to E2.

Attach the Evaporator leak test tool to the Evaporator tubes.

No

Replace the Evaporator core. Refer to this

 NOTE:

Fit new Ford green o’rings onto the Evaporator pipes before section.

installing special tool.

Connect the Low side charging station coupling to the special tool
charge port.

Evacuate the evaporator core until 30 in/hg is reached. Turn off the
Low side gauge tap. Allow the vacuum reading to stabilise for 30
minutes minimum.

 NOTE:

The pressure may rise initially as the refrigerant absorbed in

the oil will boil off, and then the vacuum reading will stabilise.

Does the vacuum reading on the Low side gauge hold steady for
a minimum of 15 minutes ?

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412-03-36 Air 

Conditioning 412-03-36

DIAGNOSIS AND TESTING (Continued)

Test Step

Result / Action to Take

E2

PRESSURE HOLDING TEST

With the special tool still attached to the evaporator inlet / outlet tubes,

Yes

charge the evaporator with refrigerant through the Low side special

The Evaporator core is not the root cause of

tool charge port.

Refrigerant leakage. Carry out full and accurate
leak testing of the remaining A/C system

Charge with approx. 100 grams of refrigerant. Turn the Low side

components using an Ultra Violet lamp or a

pressure gauge tap off. Allow the pressure reading to stabilise.

Refrigerant Leak detector. Refer to this section
(Flurorescent Dye Leak Detection or Electronic

Does the evaporator pressure reading on the Low side pressure

Leak Detection).

gauge hold steady for a minimum of 15 minutes?

No

Replace the evaporator core. Refer to Section
412-03.

PINPOINT TEST F : CONDENSER FAN OPERATION/PERFORMANCE

NOTE: Also refer to PCM section 303-14, Electro Drive Fans.

Test Step

Result / Action to Take

F1

CHECK FOR AIRFLOW OBSTRUCTION

Visually inspect A/C condenser core and radiator core for obstructions

Yes

such as leaves or bugs.

Remove obstruction and clean A/C condenser
core and radiator

Is there any obstruction ?

Retest system.

No

Go to F2.

F2

FAN SELF-TEST

The cooling fan motors and circuits are tested during a PCM key On

Yes

Engine Off Self-Test, using the WDS (Refer to section Section

Refer to DTC chart in Section 412-03 and

303-14). Faults detected by the PCM will be recorded as DTC’s.

Section 303-14.
Repair circuit, replace faulty parts, test for

 NOTE:

Prior to executing the self-test, any other DTC’s which have

normal operation.

been set should be recorded and cleared.

No

The condenser fans are not at fault.

Fan

Relay 1 Relay 2 Relay 3 Fan 1

Fan 2

Speed
OFF

OFF

OFF

OFF

OFF

OFF

LO

ON

OFF

OFF

LOW

LOW

HI

ON

ON

ON

HIGH

HIGH

Did the self-test set any DTC’s ?

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