The Bricklin SV-1 front turn signal uses a 1157 bulb size while the rear turn signal requires a 1156 bulb size. The replacement chart covers 1974 through 1976 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 Bricklin SV-1 used the 1157 bulb for the front turn signal across all three model years of its production run, 1974-1976.
The 1157 is a dual-filament bulb, meaning it carries two separate filaments within a single envelope, allowing it to serve more than one lighting function simultaneously.
The 1157 operates on a 12-volt circuit and draws 21 watts on its primary filament and 5 watts on its secondary filament, reflecting its dual-function design.
The 1157 uses a BAY15d bayonet base, which features two offset pins to ensure correct orientation during installation and to prevent substitution with single-filament bayonet bulbs.
The rear turn signal on the SV-1 used the 1156 bulb across 1974-1976, a single-filament type distinct from the dual-filament unit at the front.
The 1156 operates at 12 volts and draws 21 watts through its single filament, matching the primary wattage of the 1157 but without a secondary circuit.
The 1156 uses a BA15s bayonet base, which has a single pin and is not interchangeable with the BAY15d base of the 1157 despite the two bulbs sharing a similar physical profile.
Both the 1157 and 1156 are ANSI-standardized bulbs recognized in the United States and Canada, placing them within a widely adopted North American automotive lighting specification.
The difference in base types between the front and rear bulbs, BAY15d versus BA15s, means the two positions are not interchangeable, as the socket keyways are physically incompatible.