Chrysler 2005 Crossfire SRT6 Service Manual page 4280

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A/C EXPANSION VALVE
DESCRIPTION
The Expansion Valve is located at the front of the heater-A/C housing between the liquid and suction lines and the
Evaporator Coil. The expansion valve sprays the refrigerant into the Evaporator.
The Expansion Valve is a factory calibrated unit and cannot be adjusted or repaired. If faulty or damaged, the
expansion valve must be replaced.(Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING/A/C EXPANSION
VALVE - REMOVAL).
OPERATION
When the A/C compressor is switched on the pressure in the evaporator decreases causing the diaphragm (1) to
flex downward in an arch. The tappet (3) follows the motion of the diaphragm and presses the valve ball (4) away
from its seat against the force of the spring (5). The refrigerant is sprayed into the evaporator through the open
valve. Since the motion of the diaphragm (1) is dependent on the intake pressure as well as the temperature at the
evaporator output, only the quantity of refrigerant which can be evaporated optimally is injected.
DIAGNOSIS AND TESTING - A/C EXPANSION VALVE
The Expansion Valve is located on the engine side of the dash panel near the shock tower.
The Expansion Valve can fail in three different positions (open, closed or restricted).
• Open Position: this will result in a noisy compressor or no cooling. The cause can be a broken spring, broken
ball or excessive moisture in the A/C system. If the spring or ball are found to be defective, replace the expan-
sion valve. If excessive moisture is found in the A/C system, recycle the refrigerant.
• Closed Position: There will be low suction pressure and no cooling. This may be caused by a failed power
dome or excessive moisture in the A/C system. If the power dome on the expansion valve is found to be
defective replace the expansion valve. If excessive moisture is found recycle the refrigerant.
• Restricted Orifice: There will be low suction pressure and no cooling. This may be caused by debris in the
refrigerant system. If debris is believed to be the cause, recycle the refrigerant and replace the expansion
valve and the receiver/drier.
PLUMBING 24 - 151