Lighting System Description. Buick GL7 (Export) 2000

For 1990-2009 cars

### Halogen Bulbs

Caution: Halogen bulbs contain gas under pressure. Handling a bulb improperly could cause it to shatter into flying glass fragments. To help avoid personal injury:

• | Turn off the lamp switch and allow the bulb to cool before changing the bulb.

• | Leave the lamp switch OFF until the bulb change is complete.

• | Always wear eye protection when changing a halogen bulb.

• | Handle the bulb only by its base. Avoid touching the glass.

• | Keep dirt and moisture off the bulb.

• | Properly dispose of the used bulb.

• | Keep halogen bulbs out of the reach of children.

### Exterior Lighting

The exterior lighting system includes the following components:

• | Headlamps

• | Fog lamps

• | Front park/turn signal/sidemarker lamps

• | Rear tail/stop/turn signal lamps

• | Backup lamps

• | Stoplamps and Center High-mounted stoplamp (CHMSL)

• | License lamps

This system also includes all controls and related hardware required for proper operation of these lamps.

#### Headlamps

• | The headlamp switch on the instrument panel controls the headlamps. Turn the headlamp switch in order to light both of the headlamps and parking lamps. When the headlamp switch is turned, the following lamps will be lit:

- | Headlamps

- | License lamps

- | Headlamp position lamps

- | Tail lamps

• | The turn signal/headlamp dimmer switch lever on the steering column controls the high-beam headlamp operation. In order to change the headlamp operation from low beam to high beam (or high beam to low beam), pull the turn signal/headlamp dimmer switch lever to the full back position (until the detent is felt) and release. The high-beam indicator (blue) in the instrument cluster will light during the high-beam headlamp operation.

• | The turn signal/headlamp dimmer switch lever can be used to flash-to-pass. In order to flash-to-pass, pull the turn signal/headlamp dimmer switch lever back until both the low-beam and the high-beam headlamps are lit. DO NOT pull the lever past the detent. The low-beam headlamp operation will resume when you release the turn signal/headlamp dimmer switch lever to the original position.

#### Fog Lamps

• | The front fog lamps are mounted in the front bumper fascia.

• | The front fog lamps will light whenever the following conditions are met:

- | The fog lamp switch is in the ON position.

- | The headlamp or the parking lamp is ON.

- | The high beam headlamps are OFF.

• | The rear fog lamps are housed in the taillamp assembly.

• | The rear fog lamps will light whenever the following conditions are met:

- | The rear fog lamp switch is in the ON position.

- | The headlamp or the parking lamp is ON.

#### Front Park/Turn Signal/Sidemarker Lamps

• | The front park/turn signal/sidemarker lamps are located in a separate capsule next to the headlamp.

• | When a turn is signaled, the appropriate turn signal lamp and side marker lamp flashes in order to signal a turn. The turn signals operate only with the ignition switch in RUN. The turn signals will not operate during hazard flasher operation.

#### Headlamp Position Lamp

• | The headlamp position lamps are located in the front of the vehicle.

• | Turn the parking lamp or the headlamp switch ON at any time in order to operate the headlamp position lamps.

#### Tail Lamps

• | The rear tail lamp includes the following components:

- | Tail lamps

- | Stoplamps

- | Rear turn signal lamps

- | Rear fog lamps

• | The tail lamps are lit when the parking lamps or the headlamps are in operation.

• | Indicate a turn with the turn signal/headlamp dimmer switch in order to flash the rear turn signal lamps with the front turn signal lamps.

• | Depress the brake pedal and close the stoplamp switch in order to light the stoplamps.

• | Press the rear fog lamp switch with the headlamps on in order to operate the fog lamps.

#### Backup Lamps

• | The backup lamps are part of the tail lamp.

• | Place the transaxle in reverse in order to light the backup lamps.

#### Center High-Mounted stoplamp (CHMSL)

• | The center high-mounted stoplamps (CHMSL) is in the top of the liftgate.

• | Depress the brake pedal and close the stoplamp switch in order to light the CHMSL lights.

#### License Lamps

• | The license lamps are located under the liftgate molding handle for the liftgate latch.

• | Turn the park lamp or the headlamp switch to the ON position in order to light the license lamps.

### Interior Lighting

#### Interior Lamp Override Switch

• | The interior lamp override switch is located in the overhead console switchbank. Press the symbol on the bottom of the rocker switch in order to override the control of the interior lamps. The interior lamp override switch will disable the following lamps:

- | Cargo lamp

- | Dome lamps

- | Reading lamps

- | Instrument panel courtesy lamps

- | Instrument panel compartment lamp

- | Sunshade lighted vanity mirror lamps

- | Windshield header courtesy/reading lamps

• | Press the top of the interior lamp override switch in order to turn the power to these lamps back on. This will allow the lamps to be operated by their individual switches or by the interior lamps function of the BCM.

The instrument panel courtesy lamps, cargo lamps, dome lamps, and windshield header courtesy/reading lamps light whenever a door is opened and the interior lamp override switch is closed. The instrument panel courtesy lamps, cargo lamp, dome lamps, and windshield header courtesy/reading lamps can also be operated by placing the IP dimmer switch in the DOME position.

The dome lamps and windshield header courtesy/reading lamps can also be operated pressing the individual lamp switch.

#### Dome Lamp

• | Open one of the doors or turn the IP dimming switch to DOME in order to light the center mounted dome lamps.

• | Place the interior lamp override switch in the OFF position in order to cancel the dome lamp operation.

• | The dome lamps can also be operated by the dome lamp switches.

#### Lighted Visor Mirror

• | The lighted visor mirror, if equipped, is located next to the vanity visor mirror.

• | Raise the lighted visor mirror cover in order to light the mirror.

#### Windshield Header Courtesy/Reading Lamps

• | The front overhead console includes the following components:

- | 2 reading lamps

- | Storage compartment

- | Switchbank

• | Press the reading lamp lens in order to turn the windshield header courtesy/ reading lamps on or off.

• | The windshield header courtesy/reading lamps will also illuminate by placing the IP dimmer switch in the DOME position or when a door or the liftgate is open.

#### Reading Lamps

• | There are 2 side rail reading lamps in the third row headliner, above the outboard seating positions.

• | The rail reading lamps are operated from their individual switches.

#### Cargo Lamp

• | The cargo lamp is located in the rear of the vehicle, above the liftgate opening.

• | The cargo lamp does not have a switch. Open the doors or the liftgate in order to illuminate the cargo lamp. You may also illuminate the cargo lamp by placing the IP dimmer switch in the DOME position.

• | The cargo lamp will not operate if the interior lamps override switch is closed.

### Interior Lights Dimming

The brightness of the interior lights is changed by adjusting the position of the IP dimmer switch thumbwheel on the headlamp switch. The headlamp dimming provides a variable voltage to the system lamps and components. The following lamps or components respond directly to the voltage and are therefore capable of producing variable levels of illumination.

• | Ashtray Dimming Lamp

• | Auxiliary Blower Switch Dimming Lamp

• | Auxiliary Heater/Auxiliary A/C Switch Dimming Lamp

• | Door Lock Switch Dimming Lamp Dimming Lamp

• | Driver Info Center Dimming

• | Fog lamp switch Dimming Lamp

• | Heater A/C Control Dimming Lamp

• | Instrument Cluster Dimming Lamp

• | Instrument Panel Dimming Lamp

• | Interior Lamps Override Switch Dimming Lamp

• | Radio Dimming

• | Rear Window Switch Dimming Lamp

• | Window Switch Dimming Lamp

### Exterior and Interior Lighting

Most lighting problems are caused by the following items:

• | Loose connectors

• | Open or shorted wiring

• | Burned-out bulbs

• | Bad switches

• | Inadequate grounds

• | Open fuses

Many of these problems are repaired by replacing a part that requires a special procedure, such as a lens and housing sealed together. For these repairs, follow the instructions normally included in the replacement parts package.

When removing a component that requires special sealing items, such as sealing washers, be sure to reinstall those items when replacing the component. If any body sealing items, such as grommets, are disturbed, be sure to repair them so that the passenger compartment remains properly sealed.

Use the following general guidelines in order to diagnose a lighting system problem:

• | Verify the owner's complaint.

• | Attempt to operate the other systems that are powered through the same fuse.

| If the other systems powered through the same fuse are inoperative, replace the fuse.

• | Check for aftermarket (non-OEM) equipment.

| If add-on accessories are discovered, disconnect the system in order to make certain that the add-on is not the cause of the problem.

• | Check all connectors and related wiring to the suspect electrical component:

- | Poor mating of connector halves

- | Terminals not fully seated in the connector body (backed out)

- | Dirt or corrosion on the connector terminals.

- | The terminals must be clean and free of any foreign material which could interfere with proper terminal contact.

• | Check related ground eyelets for a clean and tight connection.