Harley-Davidson FXDL Low Rider Tail Light Bulb Size

Harley-Davidson FXDL Low Rider tail light uses 3157 and 198 bulb sizes. The replacement chart covers 1993 to 2017 production years with corresponding bulb size specifications.

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
2014-2017	3157
1993-1998	198

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3157
ANSI standard (US & Canada). Miniature wedge bulb (T5). 12V, 2W.	198

Other Locations

Additional Notes

The 3157 is an ANSI-standard dual-filament wedge bulb classified under the T25 form factor, operating at 12 volts with a wattage split of 27W for the high-filament function and 7W for the low-filament function, making it suitable for combined stop and tail light duties.
The Harley-Davidson FXDL Low Rider used the 3157 bulb as its tail light specification across the 2014-2017 model years.
The 198 is an ANSI-standard miniature wedge bulb classified under the T5 form factor, operating at 12 volts with a single 2W output, a significantly lower wattage than the 3157.
The FXDL Low Rider used the 198 bulb as its tail light specification across the 1993-1998 model years.
The T25 and T5 designations refer to the physical form factor of each bulb, with T5 being considerably smaller than T25, meaning the two bulb types are not physically interchangeable despite both being wedge-base designs.
The shift from the single-filament 2W bulb (198) to the dual-filament 27W/7W bulb (3157) reflects a fundamental difference in electrical load and circuit design between the two specification groups, requiring attention to socket and wiring compatibility.