GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the 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 RUN position.
  2. Turn the headlamp switch to the PARK position.

Do all of the following lamps turn on?:

    • The front park lamps
    • The front side marker lamps
    • The rear tail lamps
    • The rear license lamps
    • The rear side marker lamps
    • The positioning lamps (Europe and Scandinavia)

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

Go to Step 3

3

  1. Disconnect the headlamp switch.
  2. Connect a test lamp between the supply voltage circuit of the exterior lamps at the headlamp switch connector and battery voltage. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

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Go to Step 4

Go to Step 5

4

  1. Repair a short to ground in the supply voltage circuit of the exterior lamps. Refer to Wiring Repairs in Wiring Systems.
  2. Check the TAIL LPS fuse 5. If open, replace.

Did you complete the repair?

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Go to Step 10

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5

Connect a test lamp between the battery voltage circuit of the headlamps at the headlamp switch connector and ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

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Go to Step 6

Go to Step 7

6

  1. Reconnect the headlamp switch.
  2. Connect a test lamp between the supply voltage circuit of the exterior lamps at the headlamp connector and ground. Refer to Circuit Testing in Wiring Systems.
  3. Turn the park lamps on.

Does the test lamp illuminate?

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Go to Step 8

Go to Step 9

7

Repair a poor connection or an open in the battery voltage circuit of the headlamp switch. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Did you complete the repair?

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Go to Step 10

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8

Repair a poor connection or an open in the supply voltage circuit of the exterior lamps. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Did you complete the repair?

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Go to Step 10

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9

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Did you complete the replacement?

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Go to Step 10

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10

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3