GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

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

1

Did you review the headlamp description and operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Lighting Systems

2

  1. Place the headlamp switch in the HEADLAMP ON position.
  2. Place the headlamp dimmer switch in the HIGH position.

Do the high beam headlamps illuminate?

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

Go to Step 3

3

Place the headlamp dimmer switch in the LOW position.

Do the low beam headlamps illuminate?

Go to Step 4

Go to Low and High Beams Headlamps Inoperative

4

  1. Place the headlamp switch in the OFF position.
  2. Disconnect the headlamp dimmer switch connector.
  3. Connect a 30 amp fused jumper wire between the headlamp switch signal circuit and the headlamp high beam supply voltage circuit.
  4. Place the headlamp switch in the HEADLAMP position.

Do the high beam headlamps illuminate?

Go to Step 5

Go to Step 6

5

Inspect for poor connections at the harness connector of the headlamp dimmer 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, high resistance, or short to ground on the headlamp high beam supply voltage circuit. Refer to Circuit Testing or Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 8

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7

Replace the headlamp dimmer switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column-Standard.

Did you complete the replacement?

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 3