GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights 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

  1. Turn the headlamp switch to the park position.
  2. Connect a test lamp between the fused battery feed circuit and a good ground at the headlamp and panel dimmer switch to ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 6

4

Connect a test lamp from (back probe) between the park lamp switch output circuit at the headlamp and panel dimmer switch to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 9

5

Connect a test lamp between the INT PRK fuse, located in the fuse block, to a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 8

6

Repair the open in the fused battery 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 10

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7

Repair the open in the park lamp switch output circuit between the body wiring harness junction block and the engine wiring harness junction block. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 10

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8

Repair the open in the park lamp switch output circuit between the headlamp and the panel dimmer switch and the fuse block. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 10

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9

Replace the headlamp and panel dimmer switch. Refer to Headlamp Switch Replacement .

Did you complete the replacement?

Go to Step 10

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10

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3