A Symptoms

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

Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
^ Defogger Inoperative Rear Window
^ Defogger Grid Lines Diagnosis