GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Fog Lights Schematics

Connector End View Reference: Master Electrical Component List

DEFINITION: Use this chart if either the front or the rear fog lamps are ON all of the time.

1

Did you perform the Lighting System Diagnostic System Check?

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 OFF position.

Are the fog lamps off?

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

Go to Step 3

3

Remove the fog lamp relay.

Do the fog lamps turn OFF?

Go to Step 5

Go to Step 4

4

  1. Reinstall the fog lamp relay.
  2. Test for a short to battery positive voltage on the fog lamp switched battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 7

5

Test for a short to ground in the fog lamp relay control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and current the condition?

Go to Step 8

Go to Step 6

6

Replace the fog lamp relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 8

--

7

Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 8

--

8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2