Opel Frontera UE. Manual - part 17

1A–40

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

Connect The Manifold Gauge

Low-pressure hose (LOW) — Suction side
High pressure hose (HI) — Discharge side

901RX060

EndOFCallout

Legend

(1) High Side

(2) Low Side

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

1A–41

Condition

Possible cause

Correction

Discharge (High Gauge) Pressure
Abnormally High

Condenser clogged or dirty.

Clean the condenser fins

Cooling fan does not operate
properly.

Check the cooling fan operation.

Discharge (High Gauge) Pressure
Abnormally High.
Insufficient cooling.

Excessive refrigerant in system.

Discharge  and  recover  refrigerant.

Recharge to specified amount.

Discharge (High Gauge) Pressure
Abnormally High.
High pressure gauge drop.     (After
stopping A/C, the pressure drops
approx. 196kPa (28psi) quickly)

Air in system.

Evacuate  and  charge  refrigerant
system.

Discharge (High Gauge) Pressure
Abnormally Low.
Insufficient cooling

Insufficient refrigerant in system.

Check  for  leaks.  Discharge  and
recover the refrigerant. Recharge to
the specified amount.

Discharge (High Gauge) Pressure
Abnormally Low.
Low pressure gauge indicates
vacuum.

Clogged or defective expansion
valve.

Replace the expansion valve.

Discharge (High Gauge) Pressure
Abnormally Low.
Frost or dew on refrigerant line
before and after the receiver/drier or
expansion valve, and low pressure
gauge indicates vacuum.

Restriction caused by debris or
moisture in the receiver/drier.

Check system for restriction and
replace the receiver/drier.

Discharge (High Gauge) Pressure
Abnormally Low.
High and low pressure gauge
balanced quickly. (After turned off A/
C)

Compressor seal defective

Repair or replace the compressor.

Poor compression due to a defective
compressor gasket.

Repair or replace the compressor.

Suction (Low Gauge) Pressure
Abnormally High.
Low pressure gauge (Low pressure
gauge is lowered after condenser is
cooled by water.)

Excessive refrigerant in system.

Discharge  and  recover  refrigerant
Recharge to specified amount.

Suction (Low Gauge) Pressure
Abnormally High.
Low pressure hose temperature.
(Low pressure hose temperature
around the compressor refrigerant
line connector is lower than around
evaporator.)

Unsatisfactory valve operation due
to  defective temperature sensor of
expansion valve.

Replace the expansion valve.

Expansion valve opens too long.

Replace the expansion valve.

Suction (Low Gauge) Pressure
Abnormally High.
High and low pressure gauge
balanced quickly. (After turned off A/
C)

Compressor gasket is defective.

Repair or replace the compressor.

Suction (Low Gauge) Pressure
Abnormally Low.
Insufficient cooling.

Insufficient refrigerant in system.

Check  for  leaks.  Discharge  and
recover the refrigerant. Recharge to
specified amount.

Suction (Low Gauge) Pressure
Abnormally Low.
Frost on the expansion valve inlet
line

Expansion valve clogged.

Replace the expansion valve.

1A–42

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

A/C — Air Conditioning

Suction (Low Gauge) Pressure
Abnormally Low
Receiver/drier inlet and outlet
refrigerant line temperature. (A
distinct difference in temperature
develops.)

Receiver/Drier clogged.

Replace the receiver/drier.

Suction (Low Gauge) Pressure
Abnormally Low.
Expansion valve outlet refrigerant
line. (Not cold and low pressure
gauge indicates vacuum.)

Expansion valve temperature sensor
is defective.

Replace the expansion valve.

Suction (Low Gauge) Pressure
Abnormally Low.
When the refrigerant line is clogged
or blocked,     the low pressure
gauge reading will decrease, or a
vacuum reading may be shown.

Clogged or blocked refrigerant line.

Replace refrigerant line.

Suction (Low Gauge) Pressure
Abnormally Low.
Evaporator core is frozen.

Thermo switch defective.

Replace thermo switch.

Suction (Low Gauge) and Discharge
(High Gauge) Pressure Abnormally
High.
Insufficient cooling.

Excessive refrigerant in system.

Discharge 

and 

recover 

the

refrigerant, the Recharge to the
specified amount.

Condenser clogged or dirty.

Clean the condenser fin.

Suction (Low Gauge) and Discharge
(High Gauge) Pressure Abnormally
High.
Suction (Low) pressure hose (Not
cold).

Air in system.

Evacuate and charge refrigerant.

Suction (Low Gauge) and Discharge
(High Gauge) Pressure Abnormally
Low.
Insufficient cooling

Insufficient refrigerant in system.

Check  for  leaks.  Discharge  and
recover refrigerant. Recharge to
specified amount.

Condition

Possible cause

Correction

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

1A–43

Magnetic Clutch Diagnosis

D08RX249

When the air conditioning switch and the fan control
knob (fan switch) are turned on with the engine running,

current flows through the thermostat and the
compressor relay to activate the magnetic clutch.