ELECTRICAL SYSTEMS-CHASSIS - 9
169
2007 CAYMAN
Functional Test:
Start and operate the engine until
the water reaches normal operating
temperature.
Set the HVAC temperature control to the
full hot position.
Discharge air outlets should have hot air.
Rotate the temperature control to full
cold position.
Allow 10 minutes for the temperature
to stabilize.
The discharge air outlets should have
cold air.
System Components
Compressor -
The compressor is
belt driven from the engine through
the compressor and electronic clutch
pulley. The compressor will pump
freon from a low-pressure gas into a
high-pressure, high-temperature gas.
This is the start of the refrigeration
process.
Condenser -
The condenser is made
of coils and fi ns which provide rapid
transfer of heat from the refrigerant
as external air passes over the coils.
The high-pressure gas is changed to a
high-pressure liquid.
Condenser Fan -
A steady fl ow of
cooling air is maintained across the
condenser during system operations.
Receiver-Drier -
Freon leaves the
condenser, enters the receiver-drier and
is stored until needed. The drier fi lters
out moisture in the system. It only
takes one drop of moisture to cause a
malfunction in the cooling unit.
Expansion Valve -
The expansion
valve suppresses the refrigerant into
the evaporator according to the cooling
requirements. The pressure is reduced
in the restrictive effort of the expansion
valve. A part of the valve is the
capillary tube assembly. The capillary
tube is the sensing bulb at the outlet of
the evaporator.
Evaporator -
A tube core and fi ns are
used in the evaporator similar to the
condenser. Air is blown through the
fi ns to allow the evaporator to cool and
reduce pressure.
Blower and Motor -
The evaporator
has a fan called the blower. The blower
will draw air from the cab area and
force the air over the evaporator coils
and fi ns. This forced air will ensure
continuous vaporizing of the R134a.
Relays and Switches -
Both electronic
and vacuum switches are used in the
control and operations of the system.
Vacuum Generator -
The vacuum
generator is important to the operation
of the dash heating and A/C systems.
This provides the vacuum to open
and close the vacuum switches. The
vacuum generator creates 15 inches of
vacuum that is passed to a reservoir
ball. Most dash heater and A/C
systems will only require 10 inches of
vacuum to operate the switches. The
output from the reservoir is sent to the
vent control knob. The control knob
will then direct the vacuum operation
to the appropriate vacuum switch to
open or close vents and switches.
When the ignition is on and the A/C is
operating, the vacuum generator will
operate.
030947
Vacuum Generator:
Located at front fi rewall.
Summary of Contents for CAYMAN 2007
Page 12: ...GENERAL INFORMATION 1 CAYMAN 2007 8 NOTES...
Page 14: ......
Page 16: ......
Page 52: ...DRIVING SAFETY 2 CAYMAN 2007 48 NOTES...
Page 80: ...EXTERIOR INTERIOR CARE 3 CAYMAN 2007 76 NOTES...
Page 100: ...APPLIANCES 4 CAYMAN 2007 96 NOTES...
Page 132: ...WATER SYSTEMS 6 CAYMAN 2007 128 NOTES...
Page 160: ...ELECTRICAL SYSTEMS HOUSE 8 156 CAYMAN 2007 NOTES...
Page 226: ...INDEX 222 CAYMAN 2007 NOTES...
