Normal Operation

WARNING: This page is about a different car, the 2009 Mercury Sable, 2009 Ford Taurus X, and 2009 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.

Under normal operation, when the ignition switch is in the RUN or ACCESSORY position, voltage is supplied to the rear wiper relay coil through circuit CBP45 (YE). The rear wiper relay coil is grounded at all times through circuit GD120 (BK/GN). High current voltage is supplied to the rear wiper relay through circuit SBB25 (RD). When the rear wiper relay is activated it supplies voltage to the rear wiper motor through circuit CRW02 (GY/BU). The rear window wiper motor is grounded through circuit GD147 (BK/VT). The rear window wiper motor receives open and ground inputs from the multi-function switch through circuits CRW20 (GY/YE) and CRW21 (YE/VT) to activate the wiper to the appropriate modes. The multi-function switch supplies a ground input to the rear wiper motor on CRW21 (YE/VT) when INT 1 is selected. The multi-function switch supplies ground to the rear wiper motor on CRW21 (YE/VT) and CRW20 (GY/YE) when INT 2 is selected. The rear window wiper motor has a safety override which stops the rear wiper motor if it is operating when the liftgate is opened. The smart junction box (SJB) supplies a ground signal to the rear window wiper motor through circuit CPL58 (GY/OG) when the liftgate is closed. When the liftgate is opened, the SJB removes the ground signal and the rear window wiper motor stops until the liftgate is closed.

This pinpoint test is intended to diagnose the following:

Fuse(s)
Wiring, terminals or connectors
Multi-function switch
Rear window wiper motor