GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Lighting System Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn the ignition to the ON position.
  2. Press the fog lamp switch to the ON position.

Are the fog lamps on?

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Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Remove the Fog Lamp Relay.

Using a test lamp connected to a known good ground, probe the fog lamp relay switched B+ feed circuit in the Underhood Accessory Wiring Junction Block.

Does the test lamp turn on?

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Go to Step 5

Go to Step 4

4

Replace the underhood accessory wiring junction block.

Has the repair been made?

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Go to Step 8

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5

Install a fused jumper across the switched side of the Fog Lamp Relay.

Do the fog lamps turn on?

--

Go to Step 6

Go to Step 7

6

Replace the Fog Lamp Relay.

Has the repair been made?

--

Go to Step 8

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7

Repair a poor connection or an open in the fog lamp switched circuit between the underhood accessory wiring junction block and the fog lamp switch. Refer to Circuit Testing and Wiring Repairs .

Has the repair been made?

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Go to Step 8

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8

Operate the system in order to verify the repair.

Did you correct the condition?

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Go to Diagnostic System Check - Lighting Systems

Go to Step 2