GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1999 🢒 Firebird 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Interior Lights Dimming System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Turn the ignition switch to the RUN position.
  2. Turn the I/Pdimmer switch to the low intensity position.
  3. Turn the headlamp switch to the PARK position.

The following lamps are all illuminated:

    • The steering wheel radio control switches
    • The fog lamp switch
    • The door illumination
    • The HVAC control
    • The headlamp switch
    • The instrument cluster
    • The ashtray/PRNDL lamp
    • The fog lamp switch
    • The rear fog lamp switch (Export)
    • The driver seat heater switch
    • The electronic traction control switch
    • The folding top switch (Convertible)

The vacuum fluorescent (VF) display (radio) step dim.

2

Turn the I/P lamp dimmer switch slowly to the high intensity position.
  1. The brightness of the I/P lamps slowly increase to high.
  2. The VF brightness of the radio slowly increases to high.
    • Lamp intensity varies erratically. Refer to Headlamp Switch Replacement .

3
  1. Turn the I/P lamp dimmer switch to the low intensity position.
  2. Turn the headlamp switch to the OFF position.
    • The I/P lamps turn off.
    • The radio VF display turns off.

Instrument Panel Lamps Do Not Dim

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