Low Charge Protection Switch
WARNING: This page is about a different car, the 2004 Lincoln Aviator. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
It is necessary to recover the refrigerant from the A/C system before removing the low charge protection switch.
The low charge protection switch (19E561) is used to prevent A/C compressor damage in the event of a low refrigerant charge, by interrupting the ground signal circuit between the refrigerant containment switch and ground, when the low side refrigerant pressure drops below acceptable levels. The electrical switch contacts open when the suction pressure drops below normal levels. The contacts close when the suction pressure rises.
The low charge protection switch is mounted on the TXV.