Harley-Davidson FLHTCU Electra Glide Ultra Classic Brake Bulb Size

The Harley-Davidson FLHTCU Electra Glide Ultra Classic uses a 3157 bulb size for brake applications. The replacement chart covers 2012 to 2019 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	US Type	EU Type	Shop
2012-2019	3157	P27/7W	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3157	Check Price

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Additional Notes

The Harley-Davidson FLHTCU Electra Glide Ultra Classic uses the 3157 bulb for the brake light position across the 2012-2019 model years.
The 3157 is an ANSI-standardized bulb type recognized across the United States and Canada, meaning it conforms to a defined set of electrical and physical specifications shared by all compliant manufacturers.
The 3157 is a dual-filament bulb, which means it contains two separate filaments within a single housing, allowing it to serve both a low-intensity running light function at 7W and a high-intensity brake light function at 27W.
The bulb operates on a 12-volt electrical system, consistent with the standard automotive and motorcycle electrical architecture found in this platform.
The T25 designation refers to the wedge-style base of the bulb, a physical form factor that determines how the bulb seats and locks into its socket without a separate bayonet or screw mechanism.
Because the 3157 is a dual-filament type, substituting it with a single-filament equivalent such as the 3156 would result in the loss of one lighting function, making direct replacement with the correct dual-filament part a fitment requirement.