Low Washer Fluid Level Switch
WARNING: This page is about a different car, the 2017 Lincoln Navigator and 2017 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.
The low washer fluid level switch is mounted in the washer fluid reservoir and is hardwired to the IPC through a single signal wire. The low washer fluid level switch is grounded to a body ground through a separate circuit. The IPC provides a battery reference voltage to the low washer fluid level switch. When the washer fluid level is low, the float drops closing the switch and pulling the reference voltage low. When the washer fluid level is high, the float lifts off the switch and opens the circuit to the IPC sending the reference voltage high.