GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Interior Lights Dimming Schematics

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn the ignition to the ON position.
  2. Turn the headlamp switch to the PARK position.
  3. Turn the I/P dimmer switch to a LOW position.

Do the I/P lamps dim?

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

Go to Step 3

3

  1. Turn the ignition to the OFF position.
  2. Turn the headlamp switch to the OFF position.
  3. Turn the I/P dimmer switch to a LOW position.

Are the I/P lamps ON?

Go to Step 4

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

4

Are the park lamps ON?

Go to Park Lamps Always On

Go to Step 5

5

Disconnect the headlamp switch.

Are the I/P lamps ON?

Go to Step 6

Go to Step 7

6

Repair a short to battery positive voltage in the instrument panel lamp supply voltage circuit. Refer to Wiring Repairs and to Connector Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 8

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7

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

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 2