Washer Switch: Description

WARNING: This page is about a different car, the 2013 Nissan Armada. However, it is still accessible from the selected car via links, so may be relevant.

Washer switch is integrated with combination switch (wiper and washer switch).
Combination switch (wiper and washer switch) switches polarity between front washer operating and rear washer operating to supply power and ground to the front and rear washer motor.

Fig 1: Washer Switch Power Supply Diagram
Courtesy of NISSAN NORTH AMERICA, INC.