BMW 325 Dome Light Bulb Size

The BMW 325 dome light requires a 6411 bulb size for proper installation within the interior overhead lighting fixture. Data for the specified bulb covers the 1986 to 1988 range.

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
1986-1988	6411

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 36mm length, SV8.5 base. 12V, 5W.	6411

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Additional Notes

The 6411 is the dome light bulb size for the BMW 325 across the 1986-1988 model years.
The 6411 bulb follows the ANSI standard, meaning it meets the specifications set by the American National Standards Institute and is rated for use in the United States and Canada.
The 6411 is a festoon-type bulb, which is a cylindrical lamp that makes contact at both ends rather than through a screw or bayonet base.
The 6411 bulb has a 36mm length, which is a critical fitment factor, as festoon bulbs must physically span the contact points of the housing to seat correctly.
The SV8.5 base designation refers to the end-cap style of the festoon bulb, where 8.5 indicates the cap width in millimeters. A bulb with a different base designation would not seat correctly in the same housing.
The 6411 operates at 12 volts, consistent with the standard electrical system voltage of passenger vehicles from this era.
The 6411 is rated at 5 watts, placing it in the low-wattage range typical of interior courtesy lighting applications.