Triumph TR6 Brake Bulb Size

The Triumph TR6 brake light requires a 1157 bulb size for proper illumination and function. Data for the specified component covers the period from 1969 through 1976.

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
1969-1976	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 1157 is the sole brake bulb type specified for the Triumph TR6 across all listed model years, spanning 1969-1976.
The 1157 is an ANSI-standardized bulb used in the United States and Canada, operating on a 12-volt electrical system.
As a dual-filament bulb, the 1157 carries two separate wattage ratings: 21W for the high-intensity filament and 5W for the low-intensity filament, allowing it to serve both brake and running light functions within a single housing.
The 1157 uses a BAY15d bayonet base, a two-pin offset base design that physically prevents incorrect insertion by positioning its two pins at different heights.
The BAY15d base is not interchangeable with single-filament bayonet bases such as the BA15s, as those lack the second pin required to activate both filaments.