GM Service Manual Online
For 1990-2009 cars only

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Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems.

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Place the headlamp dimmer switch in the flash to pass position (FTP).

Do the high beam headlamps illuminate when the headlamp dimmer switch is in the FTP position?

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

Go to Step 3

3

  1. Turn the headlamp switch to the HEAD position.
  2. Place the headlamp dimmer switch in the HIGH position.

Do the high beam headlamps illuminate?

Go to Step 4

Go to Headlamps Inoperative - High Beams

4

  1. Disconnect connector C201.
  2. Using a test lamp connected to ground, probe the battery positive voltage circuit of connector C201.

Does the test lamp illuminate?

Go to Step 5

Go to Step 6

5

Inspect for poor connections at the harness connector of the turn signal switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 7

6

Repair an open or a high resistance in the battery supply voltage circuit of connector C201. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 8

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7

Replace the turn signal switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel Column.

Did you complete the repair?

Go to Step 8

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8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2