A Symptoms

IMPORTANT: Review the system operation in order to familiarize yourself with the system functions. Refer to the following procedures:
^ Rear Window Defogger Description
^ Automatic Day-Night Mirror Operation

Visual/Physical Inspection
^ Inspect for aftermarket devices which may affect the operation. Refer to Checking Aftermarket Accessories in Diagrams.
^ Inspect the easily accessible or visible system components for obvious damage or conditions which may cause the symptom.

Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent and Poor Connections in Diagrams.