Harley-Davidson FXDL Low Rider Turn Signal Bulb Size
Harley-Davidson FXDL Low Rider front turn signal bulbs use 198 size, while rear turn signal bulbs use P21W or 199 size. The replacement chart covers 1993 to 2017 model 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.
The two most frequently specified bulb types across the Harley-Davidson FXDL Low Rider turn signal positions are the 198 and P21W, with the 199 appearing in a single model year for the rear turn signal.
The 198 is an ANSI-standard miniature wedge bulb of the T5 form factor, rated at 12V and 2W, placing it among the lower-wattage signal bulbs used in automotive and motorcycle applications.
The P21W follows the ECE standard used in Europe and worldwide, features a BA15s single-contact bayonet base, and operates at 12V with a 21W output, making it substantially more powerful than the 198.
The 199 shares the same BA15s bayonet base and 12V, 21W electrical rating as the P21W but is classified under the ANSI standard rather than the ECE standard, and is noted as a variant of the 1156 bulb type.
The front turn signal positions on the FXDL Low Rider use the 198 bulb across the 1993-1998 model years, while the rear positions draw from a different set of bulb types entirely, indicating the front and rear circuits are not interchangeable by specification.
Although the P21W and the 199 share identical base type and wattage ratings, they originate from different standardization systems, and substituting one for the other without confirming physical and electrical compatibility with the specific socket is not supported by the specifications.
The rear turn signal on the 1994 FXDL Low Rider is specified with the 199 bulb, while the surrounding model years from 1993 and 1995-1998 use the P21W, representing a single-year divergence in rear fitment within that production period.
The front turn signal's 198 bulb, at 2W, operates at roughly one-tenth the wattage of the P21W and 199 bulbs used at the rear, a difference that reflects distinct circuit and lens design requirements between the two signal positions.