GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Interior Lights Dimming Schematics

1

Did you perform the Lighting Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify the fault is present.

Does the system operate normally?

Go to Testing for Electrical Intermittents in Wiring Systems

Go to Step 3

3

Turn the park lamps ON.

Do the park lamps function properly?

Go to Step 4

Go to Park Lamps Inoperative

4

Turn the fog lamps ON.

Do the fog lamps function properly?

Go to Step 5

Go to Fog Lamps Always On

5

  1. Ensure the panel dimmer is set to maximum.
  2. Disconnect the fog lamp switch.
  3. Connect a test lamp between the instrument panel lamp feed circuit and a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 6

6

Repair the open in the instrument panel lamp feed circuit between the switch and the body wiring harness junction block. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 8

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7

Replace the switch illumination lamp.

Did you complete the repair?

Go to Step 8

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8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3