GMC SIERRA 1999 Owner's Manual

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Bulb Replacement
For any bulb changing procedure not listed in
this section, contact your GM dealership
Service Department.
Before you replace any bulbs, be sure that all the lamps
are off and the engine isn't running. See ªReplacement
Bulbsº in the Index for the proper types of bulbs to use.
Halogen Bulbs
CAUTION:
Halogen bulbs have pressurized gas inside and
can burst if you drop or scratch the bulb. You or
others could be injured. Be sure to read and
follow the instructions on the bulb package.
Headlamps
Sealed Beam Lamps
1. Remove the four
screws from the
headlamp retainer.
2. Pull the headlamp out and remove the retainer.

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3. Unplug and remove
the headlamp.
4. Plug in the new headlamp and put it in place.
5. Install the retainer to the headlamp and tighten
the screws.Composite Headlamps
1. Remove the two hex head pins at the
locations shown
2. Pull out the headlamp lens assembly.
3. Unplug the electrical connector.

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4. Turn the bulb
counterclockwise
and remove it.
5. Put the new bulb into the assembly and turn it
clockwise until it is tight.
6. Plug in the electrical connector.
7. Put the headlamp lens assembly back into the
vehicle. Install and tighten the two hex head pins.Front Turn Signal Lamps
(Sealed Beam Headlamps)
1. Remove the two screws
at the inside edge of
the parking/turn signal
lamp assembly.
2. Remove the lamp assembly by swinging it out from
the inside edge and sliding it out at the outside edge.
3. Squeeze the tab on the side of the lamp socket while
turning the socket counterclockwise.

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4. Pull the socket out of the
lamp assembly.
5. Push in gently on
the bulb, turn it
counterclockwise
and remove it from
the socket.
6. Put the new bulb into the socket, gently press in on
the bulb and turn it clockwise until it is tight.
7. Put the socket back into the lamp assembly and turn
it clockwise until it locks.
8. Put the parking/turn signal lamp assembly back into
the vehicle and tighten the screws.Front Turn Signal Lamps
(Composite Headlamps)
1. Remove the four screws
and take out the
parking/turn signal
lamp assembly.
2. Squeeze the tab on the side of the lamp socket while
turning the socket counterclockwise.

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3. Pull the socket out of
the lamp assembly.
4. Push in gently on the bulb, turn it counterclockwise
and remove it from the socket.
5. Put the new bulb into the socket, gently press in on
the bulb and turn it clockwise until it is tight.
6. Put the socket back into the lamp assembly and turn
it clockwise until it locks.
7. Put the parking/turn signal lamp assembly back into
the vehicle and tighten the four screws.Front Sidemarker Lamps
(Composite Headlamps)
1. Remove the four screws
and pull out the
parking/turn signal
lamp assembly.
2. Reach through the opening and turn the sidemarker
bulb socket counterclockwise and remove it.

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3. Pull the bulb straight out
of the socket.
4. Put a new bulb into the socket and push it in until it
is tight.
5. Put the socket back into the sidemarker assembly
and turn it clockwise to tighten it.
6. Replace the parking/turn signal lamp assembly and
tighten the screws.Fender Marker Lamps
(Dual Rear Wheel Pickup Models)
1. Remove the screws and
take the fender marker
assembly out of
the fender.

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2. Turn the bulb socket
counterclockwise and
remove it from the
lens assembly.
3. Pull the bulb straight out of the socket.
4. Put a new bulb into the socket and push it in until it
is tight.
5. Put the socket back into the lens assembly and turn it
clockwise to tighten it.
6. Replace the lens and tighten the screws.Center High-Mounted Stoplamp (CHMSL)
1. Remove the screws and
lift off the lens.
2. Pull the old bulb straight out of the socket.

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3. Put a new bulb into the
socket and push it in
until it is tight.
4. Replace the lens and tighten the screws.Roof Marker Lamps
1. Remove the screws and lift off the lens.
2. Pull the bulb straight out of the socket.
3. Put a new bulb into the socket and push it in
until it is tight.
4. Replace the lens and tighten the screws.
Pickup Box Identification Lamps (Dual
Rear Wheel Pickup Models)
1. Remove the screws and lamp assembly.
2. Unplug the lamp assembly harness.
3. Use a screwdriver to gently pry the individual lamp
from the lamp housing.
4. Unplug the lamp at the connector.
5. Plug in a new lamp and snap it into the housing.
6. Reinstall the lamp housing.

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6-47 Taillamps (Pickup Models)
1. Open the tailgate.
2. Remove the two rear
lamp assembly screws
near the tailgate latch
and pull out the
lamp assembly.
3. Remove the screws
from the bulb retainer
and take it off the
lamp assembly.
4. Pull the old bulb straight
out of the socket.

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5. Put in a new bulb and push it straight in until it
is tight.
6. Replace the bulb retainer.
7. Replace the rear lamp assembly and tighten
the screws.
8. Close the tailgate.
Taillamps (Chassis Cab Models)
1. Using your hands, peel the rubber seal away from
the lens.
2. Lift the lens off the
lamp assembly.
3. Slide the socket out of the lamp assembly.
4. Push in gently on
the bulb, turn it
counterclockwise
and remove it from
the socket.
5. Put in a new bulb and, pushing in gently, turn it
clockwise until it is tight.
6. Put the socket back in the lamp assembly and replace
the lens and lens seal.