Harley-Davidson FLHC Heritage Classic Tail Light Bulb Size

Harley-Davidson FLHC Heritage Classic tail light uses a 3157 bulb size for replacement applications. The replacement chart covers 2018 to 2020 model 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
2018-2020	3157

Bulb Specifications

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

Other Locations

Additional Notes

The 3157 is an ANSI-standardized bulb type recognized across the United States and Canada, placing it within a widely distributed specification category.
The Harley-Davidson FLHC Heritage Classic uses the 3157 bulb for its tail light across the 2018-2020 model years.
The 3157 is a dual-filament bulb, meaning it carries two separate filaments within a single housing to serve both the running light and brake light functions simultaneously.
The bulb operates on a 12-volt electrical system, with the two filaments rated at 27 watts and 7 watts respectively, where the higher wattage filament corresponds to the brighter brake light function.
The T25 designation refers to the wedge-style base of the bulb, which is a push-in type that does not require a bayonet or screw rotation to seat into its socket.
The dual-filament nature of the 3157 means that a single-filament substitute would not replicate the full electrical behavior of the original specification, as one of the two lighting functions would be absent.