Volkswagen Fastback front turn signal bulbs measure 1157 in size, while rear turn signal bulbs measure 1156 in size. The replacement chart covers 1969 through 1973 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 Volkswagen Fastback uses two distinct turn signal bulb types across its front and rear positions: the 1157 for the front and the 1156 for the rear, both standardized under ANSI specifications recognized in the United States and Canada.
The 1157 bulb is a dual-filament type, meaning it contains two separate filaments within a single envelope, allowing it to serve more than one lighting function simultaneously, such as turn signaling and parking illumination.
The 1157 operates at 12 volts with a wattage rating of 21W on its primary filament and 5W on its secondary filament, reflecting its dual-function design.
The 1157 uses a BAY15d bayonet base, which features two offset pins at different heights to prevent incorrect insertion and to distinguish it from single-filament bayonet bulbs.
The 1156 bulb is a single-filament type rated at 12 volts and 21W, dedicated solely to the rear turn signal function on the Volkswagen Fastback.
The 1156 uses a BA15s bayonet base, which has two pins at the same height. This base is not interchangeable with the BAY15d base of the 1157, as the pin configurations differ.
The front turn signal position of the Volkswagen Fastback (1969-1973) consistently specifies the 1157 bulb across all listed model years.
The rear turn signal position of the Volkswagen Fastback (1969-1973) consistently specifies the 1156 bulb across all listed model years.
Because the 1156 and 1157 share the same 15mm base collar width but differ in pin alignment, substituting one for the other is not physically compatible without modification.