INFINITI Q45 Dome Light Bulb Size

The INFINITI Q45 dome light utilizes DE3175 and 194 bulb sizes for the interior lighting system components. Data for the specified vehicle covers the range from 1990 through 2004.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
2004	DE3175
1999-2001	DE3175 (Front)
1998	DE3175
1997	DE3175 (Front)
1994-1996	DE3175
1993	194 (Early Model)
1993	DE3175 (Late Model)
1990-1992	194

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 31mm length, end-cap contacts. 12V.	DE3175
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 3.78W.	194

Other Locations

Additional Notes

The DE3175 is a festoon-type bulb measuring 31mm in length with end-cap contacts, operating at 12V. Festoon bulbs seat horizontally between two spring-loaded contact points rather than inserting into a socket, which is a distinct mounting method from wedge-type bulbs.
The 194 is a miniature wedge bulb of the T10 form factor, rated at 12V and 3.78W. Wedge bulbs use a pinched glass base as the contact point, eliminating the need for a separate metal base.
Both the DE3175 and 194 are ANSI-standardized bulbs for the US and Canadian markets, meaning their physical and electrical specifications conform to a defined industry standard rather than a proprietary format.
The INFINITI Q45 uses the DE3175 for its dome light across the 1994-2001 and 2004 model years, as well as the 1996 and 1998 model years, making it the predominant dome light bulb type across the model's production span covered in these specifications.
The 194 wedge bulb was specified for the dome light on the 1990-1992 Q45 model years, indicating a different interior lighting assembly was used during the earlier production period.
The 1993 Q45 carried two separate dome light bulb specifications depending on production timing. Early model units used the 194 wedge bulb, while late model units used the DE3175 festoon bulb, reflecting a mid-year assembly change.
Because the DE3175 and 194 use fundamentally different mounting systems, end-cap festoon versus wedge base, the two bulb types are not interchangeable without a corresponding change in the socket or housing.
The 1997, 1999, 2000, and 2001 model year entries each carry a "Front" designation alongside the DE3175 specification, indicating the bulb size listed applies specifically to the front dome light position for those years.
The absence of a positional qualifier on the 1994, 1995, 1996, 1998, and 2004 DE3175 entries, compared to the labeled "Front" entries in other years, reflects a difference in how the specifications categorize dome light positions across model years.