GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Place the headlamp switch in the headlamps ON position.
  2. Place the headlamp dimmer switch in the LOW BEAM position.
  3. Observe the headlamps.
  4. Place the headlamp dimmer switch in the HIGH BEAM position.
  5. Observe the headlamps.

Do both the low and high beam headlamps illuminate?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Test the headlamp ground circuit of the headlamp switch for an open or high resistance.

Did you find and correct the condition?

Go to Step 6

Go to Step 4

4

Inspect for poor connections at the harness connector of the headlamp switch.

Did you find and correct the condition?

Go to Step 6

Go to Step 5

5

Replace the headlamp switch.

Did you complete the replacement?

Go to Step 6

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6

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3