The Austin Mini Cooper front turn signal requires a 1157 or 1034 bulb size, while the rear turn signal uses a 1157 or 1073 bulb size. The replacement chart covers 1964 through 1969 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 Austin Mini Cooper uses two distinct bayonet base types across its turn signal bulb specifications: the BAY15d double-contact base, found in dual-filament bulbs, and the BA15s single-contact base, found in single-filament bulbs. These two base types are not interchangeable.
The 1034 bulb, specified for the front turn signal on the Austin Mini Cooper from 1964-1967, is a dual-filament ANSI-standard type rated at 12V and 21/5W with a BAY15d bayonet base. It is classified as a variant of the 1157.
Because the 1034 is a variant of the 1157, both share the BAY15d base and the same 12V, 21/5W rating. However, they carry different ANSI designations, and substitution between them warrants verification of exact electrical and physical compatibility before use.
The 1157 bulb, specified for both the front and rear turn signals in 1969, is a dual-filament ANSI-standard type rated at 12V and 21W/5W with a BAY15d bayonet base. Its dual-filament design allows it to serve both turn signal and parking light functions from a single socket.
The 1073 bulb, specified for the rear turn signal from 1964-1967, is a single-filament ANSI-standard type rated at 12V and 13W with a BA15s bayonet base. As a single-filament bulb, it serves only one lighting function per socket.
The 1073 is described as a lower wattage variant of the 1156. The 1156 operates at 12V and 21W, while the 1073 operates at 13W, meaning the two are not electrically equivalent despite sharing the BA15s base type.
The front and rear turn signal positions on the Austin Mini Cooper do not share the same bulb type for any model year in the specifications. The front uses dual-filament bulbs throughout, while the rear uses a single-filament bulb from 1964-1967 before transitioning to a dual-filament type in 1969.
In 1969, the Austin Mini Cooper front and rear turn signals both use the 1157, making it the only model year in the specifications where a single bulb type covers both positions.