The Triumph TR7 front and rear turn signal bulbs both utilize a 1156 size bulb for proper illumination. The replacement chart covers 1975 to 1981 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Triumph TR7 uses the 1156 bulb for both front and rear turn signals across all model years covered in the specifications, spanning 1975-1981.
The 1156 is a single-filament bulb, meaning it is designed to perform one lighting function rather than serving dual purposes such as combined stop and tail operation.
The 1156 operates at 12 volts and 21 watts, which places it within the standard range for automotive turn signal applications.
The bulb uses a BA15s bayonet base, a single-contact fitting where the "s" designation indicates a single pin, as opposed to the offset dual-pin BA15d base found on two-filament bulbs.
The 1156 conforms to ANSI standards and is specified for use in the United States and Canada, reflecting a standardized North American fitment.
Because the front and rear turn signal positions share the same 1156 specification across the entire 1975-1981 production run of the TR7, a single bulb type serves all four turn signal housings on the vehicle.
The BA15s bayonet base is not interchangeable with the BA15d base; substituting a dual-contact bulb in a single-contact socket is not supported by the fitment specification.