Rear Window Defrost
WARNING: This page is about a different car, the 2008 Mercury Mariner and 2008 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The heating ventilation air conditioning (HVAC) module controls the rear window defrost grid and heated mirrors (if equipped) by controlling the state of the rear window defrost relay. When the rear window defrost switch (integral to the HVAC module) is pressed, the HVAC module will activate the rear window defrost relay. When the relay is active, both the rear window defrost grid and the heated exterior rear view mirror glass elements are energized.
The HVAC module will deactivate the rear window defrost relay when one of the following conditions is met:
- The rear window defrost switch is pressed when the feature is active
- The ignition switch state is changed from ON to OFF/LOCK
- The 15-minute timing function is complete