For 1990-2009 cars

The headlamp and the instrument panel (IP) lamp dimmer switch control the brightness of the incandescent lamps and the vacuum fluorescent (VF) displays. The incandescent lamps are located in various components (see schematics).

The VF display is located in the following components:

• | The radio

• | The PRNDL

• | The driver information display (if equipped)

• | The radio rear speaker amplifier (if equipped)

### Incandescent Dimming

The brightness of the incandescent lamps is determined by a variable voltage signal produced by the headlamp and the IP lamp dimmer switch through CKT 8.

### Vacuum Fluorescent (VF) Dimming

The brightness of the VF display is controlled by the following 2 signals:

• | The park lamp signal (CKT 9)

• | The VF dim signal (CKT 308)

With the park lamps activated, the following components will dim for night time viewing:

• | The VF display of the radio

• | The PRNDL

• | The driver information display (if equipped)

• | The radio rear seat audio control (if equipped)

When the park lamps ON signal is not present, (park lamps are in the OFF position), the VF display is at its high brightness for daytime viewing. The headlamp and the (IP) lamp dimmer switch provide a dimming signal through CKT 308. This controls the brightness of the VF display when the headlamp and the IP lamp dimmer switch is adjusted.

### Daytime Running Lamp (DRL) Dimming

When the DRL module has the headlamps ON (in night mode) and the park light switch is OFF, voltage is fed back to the headlamp switch assembly through CKT 9. This allows the dimming circuits to function as stated above.