The front parking/turn signal lamps are located in the left and right side composite headlamp housings (GM also calls them headlamp capsules). The parking lamps can be operated any time using the headlamp switch. When a turn is signaled, the appropriate front parking lamp switches to signal a turn. The turn signals operate only with the ignition switch in the RUN position and will not operate during hazard flasher operation.
Look the job over carefully. On some vehicles, the parking and turn signal lamp bulbs can be replaced by simply twisting the socket free and replacing the bulb. On other vehicles, the lamp assembly must be removed.
- Open the hood.
- If the parking/turn signal bulb can be accessed, twist the socket to free it from the lamp assembly and withdraw the socket and bulb assembly.
- If the parking/turn signal bulb cannot be accessed, remove the lamp assembly. Twist the socket to free the locking tabs and withdraw the socket and bulb assembly. Some applications may use a locking tab that needs to be depressed so the socket can be rotated.
Fig. 1: This parking lamp/turn signal socket has a locking tab that needs to be depressed to rotate the socket
Fig. 2: Depress the locking tab with your thumb, then rotate the socket to remove
Fig. 3: With the socket free, the bulb can be replaced
Fig. 4: Carefully push in the bulb and turn it counterclockwise to unlock it
The side marker lights are located on the sides of the headlamp assemblies. These lamps will light when the headlamp or parking lights are ON. If the headlamp or parking lamps are OFF when a turn is signaled, the appropriate side marker lamp will flash in unison with the with the front turn signal lamp. If the headlamps or parking lamps are ON when a turn is signaled, the side marker lamp and the front turn signal lamp will flash alternately.
- On some applications, the marker lamp bulb socket can be accessed through the engine compartment or from under the front valence panel. On other applications, the headlamp assembly should be removed for access.
Fig. 5: On some applications, the side marker bulb socket can be accessed through the engine compartment or from underneath
Fig. 6: On this application, the side marker bulb lamp is part of the headlamp assembly
Fig. 7: Twist the socket to unlock it and pull the bulb from the socket
- The side marker lamp socket simply twists to remove.
- The bulb is a baseless bulb and just pulls out of the socket.
- Inspect the socket. They are often subject to road splash, dirt and corrosion. Clean as required.
- Install a new bulb and reassemble in the reverse order of removal.
The taillamps, stoplamps and rear turn signals lamps are all incorporated into the rear taillamps. The taillamps are lit whenever the parking lamps or headlamps are in operation. The rear turn signal lamps flash with the front turn signal lamps whenever a turn is indicated with the turn signal/headlamp dimmer switch. The stoplamps light whenever the brake pedal is depressed and the stoplamp switch is closed.
Fig. 8: The trim panel is likely held in place with retainers like this. Back out the screw to release tension on the pin legs and remove the fastener
Fig. 9: The taillamp is retained by plastic wingnuts
Fig. 10: Remove the plastic wing nuts from the taillamp housing
Fig. 11: Remove the taillamp housing from the vehicle to service the light bulbs
- Open the rear compartment (trunk).
- If equipped, unhook the convenience net that stretches between the taillamps. It is attached to hooks molded into the plastic taillamp assembly retaining wingnuts. Loosen the rear compartment trim panel. It is retained by plastic pins with a screw in the center. Back out the screw to release any tension on the plastic pin legs, and pull the trim (thin carpet-like material) for access to the taillamps.
- Remove the plastic taillamp assembly retaining wingnuts.
- Remove the taillamp assembly from the vehicle and service the light bulbs as required.
- Installation is the reverse of the removal process.
- Test the lights for correct operation.
The high-mounted stoplamp is in the center of the rear window and lights whenever the brake pedal is depressed and the stoplamp switch is closed. The bulbs are accessed from inside the trunk.
Fig. 12: This Grand Prix had a slotted vent panel covering the high-mounted stoplamp assembly. Squeeze the ends to remove or install
Fig. 13: A quarter-turn removes the socket so the bulb can be serviced
- Open the trunk.
- If equipped with a slotted vent panel, remove it from the access opening by squeezing the ends and pulling down.
- Reach through the access opening and turn the bulb socket 1⁄4 -turn counterclockwise to remove the socket. Most applications will use two sockets/bulbs. Verify that the correct bulb is being replaced.
- Replace the bulb as required.