GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Turn the ignition switch to the ON position.
  2. Turn the headlamp switch to the PARK position.
  3. Use the dimmer switch to increase and decrease the brightness of the interior lamps.

The interior lamps increase and decrease brightness when controlled by the dimmer switch.

The interior lamps do not increase or decrease brightness. Refer to Incandescent Lamps Do Not Dim for diagnosis.

2

  1. Turn the ignition switch to the ON position.
  2. Turn the headlamp switch to the PARK position.
  3. Use the dimmer switch to increase and decrease the brightness of the interior lamps.

The interior lamps increase and decrease brightness when controlled by the dimmer switch.

The interior lamps stay ON at all times or the interior lamps do not turn ON at all. Refer to Incandescent Lamps Do Not Dim for diagnosis.

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.