What Size Bulbs Does a 2004 Mitsubishi Diamante 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 2004 Mitsubishi Diamante Have?
The 2004 Mitsubishi Diamante features an extensive lighting system with 12 bulb positions. It uses halogen technology with a single 9003 LED dual-filament bulb handling both low and high beams. The Diamante has been available from 1992 to 2004, and the 2004 model falls in the late-generation years.
Can You Put LED Bulbs in a 2004 Mitsubishi Diamante?
Upgrading the 2004 Mitsubishi Diamante to LED headlights is straightforward since it uses a single 9003 LED dual-filament bulb for both low and high beams. You only need one pair of LED bulbs to upgrade both functions. Look for a 9003 LED LED kit that specifically supports dual-filament operation to ensure both beams work correctly. For the fog lights, a 9006 LED LED bulb provides a clean white output that pairs well with LED headlights.
How to Replace Bulbs on a 2004 Mitsubishi Diamante
The 9003 bulb uses a spring clip retainer with a three-prong base identical to H4. 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 2004 Diamante 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 9006 LED fog light socket.
Full Upgrade Bundle
Upgrade All 12 Positions at Once
2004 Mitsubishi Diamante Complete Bulb Size Chart
| Position | Bulb Size | Shop |
|---|---|---|
Low Beam | 9003 LED | Buy 9003 LED |
High Beam | 9003 LED | Buy 9003 LED |
Fog Light | 9006 LED | Buy 9006 LED |
Brake Light | 921 LED | Buy 921 LED |
Side Marker | 168 LED | Buy 168 LED |
Turn Signal Front | 1156 LED | Buy 1156 LED |
Turn Signal Rear | 7440NA LED | Buy 7440NA LED |
Dome Light | DE3175 | Buy DE3175 |
Map Light | 168 | Buy 168 |
Parking Light | 168 | Buy 168 |
Reverse Light | 921 | Buy 921 |
Trunk Light | DE3022 | Buy DE3022 |
Want to upgrade everything at once?
Shop Complete LED Kit for 2004 Mitsubishi DiamanteHow Long Do 2004 Mitsubishi Diamante Headlight Bulbs Last?
Standard halogen headlights on the 2004 Mitsubishi Diamante 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 22 years old, the original bulbs on your Diamante 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 2004 Mitsubishi Diamante?
The 9003 low beam bulb on the 2004 Mitsubishi Diamante is cross-compatible with H4, HB2 bulbs. These share the same physical base and electrical connection, so they will fit the socket. However, 9003 is the recommended size because it is optimized for the wattage and beam pattern designed into your headlight housing. The 9003 is a dual-filament bulb, meaning one bulb contains two separate filaments for low and high beams. This is a different design from single-filament bulbs like H11 or 9005. Make sure any LED replacement is specifically designed for dual-filament operation. 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.
2004 Mitsubishi Diamante Headlight FAQ
Did Mitsubishi Diamante Bulb Sizes Change Over the Years?
Over its production run from 1992 to 2004, the Mitsubishi Diamante has seen bulb size changes in the Low Beam, High Beam and Fog Light positions. The 2004 model uses the newer bulb specification introduced around 2003. Always verify the exact bulb size for your specific 2004 model year using the chart above, as using the wrong size can result in poor fitment or reduced light output.
Other Diamante Years
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Other Vehicles That Use 9003 LED Bulbs
These vehicles from other makes also use a 9003 LED low beam bulb: