Dodge Conquest front turn signal bulbs use 1156 size while rear turn signal bulbs use 1157 size. The replacement chart covers vehicle production spanning 1984 to 1986.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Dodge Conquest uses two distinct bulb types across its turn signal positions for the 1984-1986 model years: the 1156 at the front and the 1157 at the rear.
The 1156 is a single-filament bulb rated at 12V and 21W, built to ANSI standards for use in the United States and Canada.
It uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin offset, which prevents incorrect installation of dual-contact bulbs in the same socket.
The 1157 is a dual-filament bulb also rated at 12V, but carries two wattage ratings: 21W for the high-intensity filament and 5W for the low-intensity filament.
The 1157 uses a BAY15d bayonet base, a two-contact fitting with offset pins, which physically distinguishes it from the BA15s base of the 1156 and prevents cross-installation between the two types.
Both bulb types conform to ANSI standards, meaning they are standardized for the North American market and share common specifications across manufacturers.
The dual-filament design of the 1157 allows the rear turn signal position to serve more than one lighting function, with each filament operating independently at different power levels.
Because the 1156 and 1157 use different bayonet base configurations, the two bulb types are not interchangeable with each other despite sharing the same 12V operating voltage.