What Size Bulbs Does a 1999 Cadillac Seville Use?
Correct headlight, fog light, and tail light bulb sizes. Sourced from OEM catalog data.
Installation Difficulty
Easy (Plug and Play)
Est. Replacement Cost
$15 - $40 (Halogen) / $30+ (LED)
What Lighting System Does the 1999 Cadillac Seville Have?
The 1999 Cadillac Seville features an extensive lighting system with 12 bulb positions. It uses halogen technology with 9006 LED low beams and 194 high beams in a dual-bulb configuration. The Seville has been available from 1998 to 2004, and the 1999 model falls in the early-generation years.
Can You Put LED Bulbs in a 1999 Cadillac Seville?
To upgrade the 1999 Cadillac Seville headlights to LED, you will need a 9006 LED LED kit for the low beams and a 194 LED kit for the high beams. Start with the low beams since they are used most often and have the biggest impact on nighttime visibility. For the fog lights, a 880 LED LED bulb provides a clean white output that pairs well with LED headlights.
How to Replace Bulbs on a 1999 Cadillac Seville
The 9006 bulb uses a push-and-twist L-shaped bayonet lock. To remove the old bulb, disconnect the wiring harness first, then twist the bulb counter-clockwise and pull it out. Older model years like the 1999 Seville typically offer easy access to the headlight bulbs from behind the headlight assembly under the hood. Most owners can complete the swap in under 10 minutes per side. When installing the new bulb, avoid touching the glass with bare fingers. Skin oils create hot spots that shorten bulb life. Wear clean gloves or handle the bulb by its plastic base only. The fog lights are accessed from underneath the front bumper. You may need to remove a few plastic clips or screws from the fender liner to reach the 880 LED fog light socket.
Full Upgrade Bundle
Upgrade All 12 Positions at Once
1999 Cadillac Seville Complete Bulb Size Chart
| Position | Bulb Size | Shop |
|---|---|---|
Low Beam | 9006 LED | Buy 9006 LED |
High Beam | 194 | Buy 194 |
Fog Light | 880 LED | Buy 880 LED |
Brake Light | 194 | Buy 194 |
Side Marker | 194 LED | Buy 194 LED |
Turn Signal Front | 3157NA LED | Buy 3157NA LED |
Turn Signal Rear | 3057 LED | Buy 3057 LED |
License Plate | 194 | Buy 194 |
Map Light | 168 | Buy 168 |
Parking Light | 3157NA | Buy 3157NA |
Reverse Light | 1156 | Buy 1156 |
Trunk Light | 561 | Buy 561 |
Want to upgrade everything at once?
Shop Complete LED Kit for 1999 Cadillac SevilleHow Long Do 1999 Cadillac Seville Headlight Bulbs Last?
Standard halogen headlights on the 1999 Cadillac Seville have an expected lifespan of 500 to 1,000 hours, which works out to roughly 2 to 3 years of normal use. Signs of a failing halogen bulb include noticeably dimmer output, a yellowish tint compared to the other headlight, or intermittent flickering. At 27 years old, the original bulbs on your Seville are likely overdue for replacement. Even if they still illuminate, reduced brightness significantly impacts nighttime safety. When one headlight burns out, replace both sides at the same time. Bulbs from the same batch age at similar rates, and mismatched brightness is distracting to oncoming drivers.
What Bulbs Are Compatible with the 1999 Cadillac Seville?
The 9006 low beam bulb on the 1999 Cadillac Seville is cross-compatible with HB4 bulbs. These share the same physical base and electrical connection, so they will fit the socket. However, 9006 is the recommended size because it is optimized for the wattage and beam pattern designed into your headlight housing. Using the wrong bulb size can cause improper beam patterns that reduce your visibility and blind other drivers. It can also cause overheating inside the headlight housing, potentially warping the plastic lens or reflector. Always verify the bulb number before purchasing.
1999 Cadillac Seville Headlight FAQ
Did Cadillac Seville Bulb Sizes Change Over the Years?
Over its production run from 1998 to 2004, the Cadillac Seville has seen bulb size changes in the High Beam, Brake Light and Turn Signal Front positions. The 1999 model uses the earlier bulb specification that was in place before the change around 2001. Always verify the exact bulb size for your specific 1999 model year using the chart above, as using the wrong size can result in poor fitment or reduced light output.
Other Seville Years
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Other Vehicles That Use 9006 LED Bulbs
These vehicles from other makes also use a 9006 LED low beam bulb: