The Lincoln Mark VII brake light utilizes 1157, 2458, and 3157 bulb sizes depending on the specific production period for the vehicle. Available data covers the span from 1984 through 1992.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Lincoln Mark VII uses two distinct bulb types across its brake light specifications: the 3157 and the 1157. Both are dual-filament bulbs operating at 12 volts, designed to serve separate brightness levels for stop and tail light functions within a single housing.
The 3157 is a T25 wedge-style dual-filament bulb rated at 27W for the brake filament and 7W for the running light filament. It fits the Lincoln Mark VII brake lights for the 1989-1992 model years.
The 1157 uses a BAY15d bayonet base rather than a wedge mount, rated at 21W and 5W for its two filaments respectively. It fits the brake lights on the 1984-1988 model years.
Because the 3157 uses a wedge base and the 1157 uses a bayonet base, these two bulb types are not physically interchangeable despite both being dual-filament 12V units. Substituting one for the other is not possible without a socket adapter.
The wattage difference between the 3157 and 1157 is notable. The 3157 produces a brighter stop light output at 27W compared to the 1157 at 21W, while the 1157 draws slightly more power on its running filament at 5W versus the 3157 at 7W.
Both the 3157 and 1157 conform to ANSI standards applicable in the United States and Canada, indicating standardized electrical and physical tolerances across manufacturers producing these bulb types.
The Center High Mount Stop Light on the Lincoln Mark VII uses the 912 bulb for the 1986-1992 model years. This is a single-filament wedge bulb of the T15 type, rated at 12V and 12W.
The 912 is a variant of the 921 bulb. Both share the same T15 wedge base and 12V rating, though they differ in wattage. The 921 is rated at 16.8W, making the two bulbs not directly interchangeable in all applications without confirming socket and circuit compatibility.
The single-filament design of the 912 reflects its dedicated stop light role in the Center High Mount position, where a combined tail and brake function is not required.
All three bulb types listed in the Lincoln Mark VII brake specifications, the 3157, 1157, and 912, are ANSI-standardized, meaning equivalent bulbs from different manufacturers are produced to the same base and voltage specifications.