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 review the headlamps 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 position.
  2. Place the headlamp dimmer switch in the HIGH position.

Does the high beam indicator illuminate?

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

Go to Step 3

3

Do the high beam headlamps operate properly?

Go to Step 4

Go to Headlamps Inoperative - High Beams

4

  1. Place the headlamp switch in the OFF position.
  2. Disconnect the instrument panel cluster (IPC).
  3. Probe the headlamp high beam supply voltage circuit of the high beam indicator, with a test lamp that is connected to a good ground.
  4. Turn ON the high beam headlamps.

Does the test lamp illuminate?

Go to Step 5

Go to Step 9

5

Connect the test lamp between the headlamp high beam supply voltage circuit of the high beam indicator and the high beam Indicator ground circuit.

Does the test lamp illuminate?

Go to Step 6

Go to Step 10

6

Inspect for poor connections at the high beam indicator bulb and socket. 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 12

Go to Step 7

7

  1. Replace the high beam indicator bulb.
  2. Turn ON the high beam headlamps.

Does the high beam indicator illuminate?

Go to Step 12

Go to Step 8

8

Inspect for poor connections at the harness connector of the IPC. 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 12

Go to Step 11

9

Repair an open, high resistance or a short to ground in the headlamp high beam supply voltage circuit of the high beam indicator.

Did you complete the repair?

Go to Step 12

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10

Repair an open or high resistance in the high beam indicator ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 12

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11

Replace the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.

Did you complete the replacement?

Go to Step 12

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12

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2