The Austin Mini 850 uses a 1034 bulb size for front turn signals and a 1073 bulb size for rear turn signals. A replacement chart covering 1964 to 1967 documents the bulb specifications for this vehicle model across its production years.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Austin Mini 850 uses two distinct bulb types across its turn signal positions for the 1964-1967 model years: the 1034 at the front and the 1073 at the rear.
The 1034 is an ANSI-standard bulb recognized in the US and Canada. It operates on a 12V system and carries a dual-filament design rated at 21/5W, meaning one filament handles higher-intensity signaling while the other handles a lower-intensity function.
The 1034 uses a BAY15d bayonet base. The offset pins of the BAY15d base are a physical safeguard against incorrect installation, as the asymmetric pin placement allows the bulb to seat in only one orientation.
The 1034 is a variant of the more widely available 1157. This relationship indicates a degree of interchangeability, though the specific electrical characteristics of the 1034 should be confirmed against the application before substitution.
The 1073 is also an ANSI-standard bulb recognized in the US and Canada. It is a single-filament bulb rated at 12V and 13W, dedicated solely to the rear turn signal function on the Austin Mini 850 across all four listed model years.
The 1073 uses a BA15s bayonet base. Unlike the BAY15d, the BA15s base has symmetrically placed pins, which is consistent with single-filament bulbs where polarity orientation is less critical.
The 1073 is a lower wattage variant of the 1156. As with the 1034 and 1157 relationship, direct substitution of a 1156 for a 1073 would introduce a higher wattage draw and may not be appropriate without verifying circuit compatibility.
The front and rear turn signal positions on the Austin Mini 850 are not interchangeable with each other, as the 1034 and 1073 use different base types, BAY15d and BA15s respectively, which are physically incompatible.