GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Fog Lights Schematics

1

Did you review the Lighting System Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Lighting Systems

2

Verify that the fog lamps are always ON.

Does the system operate normally?

Go to Testing for Electrical Intermittents in Wiring Systems

Go to Step 3

3

Remove the fog lamp relay.

Did the fog lamps turn OFF?

Go to Step 5

Go to Step 4

4

Repair the short to voltage in the fog lamp supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and complete the repair?

Go to Step 9

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5

Disconnect the headlamp switch.

Did the fog lamps turn OFF?

Go to Step 8

Go to Step 6

6

Inspect the fog lamp ground signal circuit between the headlamp switch assembly and the fog lamp relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and complete the repair?

Go to Step 9

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7

Replace the fog lamp relay. Refer to Circuit Protection - Fusible Links in Wiring Systems.

Did you complete the replacement?

Go to Step 9

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8

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Did you complete the replacement?

Go to Step 9

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9

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3