A/C Expansion Valve

WARNING: This page is about a different car, the 2002 Dodge Intrepid, 2002 Chrysler Intrepid, 2002 Chrysler Concorde, and 2002 Chrysler 300M. However, it is still accessible from the selected car via links, so may be relevant.

The expansion valve can fail in three different positions (open, closed or restricted). Note, that in each case, it is defective and requires replacement:

In a 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 expansion valve. If excessive moisture is found in the A/C system, recycle the refrigerant.
In a 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.
A 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 filter/drier.