Schematic Reference: Defogger Schematics

Did you review the Rear Window Defogger system operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Stationary Windows

1. Turn ON the ignition, with the engine OFF.
2. Command the rear window defogger indicator ON and OFF, by depressing the rear window defogger switch.
3. Observe the rear window defogger indicator on the HVAC Control Assembly.

Does the rear window defogger indicator turn ON and OFF with each command?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

1. Turn OFF the ignition.
2. Disconnect the harness connector C4 of the HVAC Control Assembly.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the supply voltage circuit of the rear window defogger grid and a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 4

Inspect for poor connections at the harness connector of the HVAC Control Assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 6

Repair a short to battery positive voltage in the supply voltage circuit of the rear window defogger grid. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 7

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Replace the HVAC Control Assembly. Refer to Heater and Air Conditioning Control Replacement in HVAC Systems - Manual.

Did you complete the replacement?

Go to Step 7

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2