Freightliner FL70 Brake Bulb Size

The Freightliner FL70 brake light uses a 1157 bulb size for the lighting components. Available information covers the period from 1991 through 2005 for the specified vehicle.

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
1991-2005	1157

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V, 21W/5W.	1157

Other Locations

Additional Notes

The Freightliner FL70 uses the 1157 bulb for its brake light application across all listed model years, spanning 1991-2005.
The 1157 is an ANSI-standardized bulb recognized across the United States and Canada, meaning it conforms to a defined set of electrical and physical specifications shared by multiple manufacturers.
It is a dual-filament bulb, which allows a single unit to serve two distinct brightness levels within the same housing. In brake light applications, the higher-output filament activates under braking while the lower-output filament typically handles a secondary function such as a tail or running light.
The 1157 operates on a 12-volt electrical system and draws 21 watts on its high-intensity filament and 5 watts on its low-intensity filament.
The bulb uses a BAY15d bayonet base, a two-pin offset base design. The offset pin placement is a deliberate fitment control, as it prevents incorrect insertion of a single-filament bulb into a socket intended for a dual-filament unit.
Because the BAY15d base uses offset pins, a physically similar but non-offset bayonet base bulb is not interchangeable with the 1157, even if the outer profile appears close in size.