Volkswagen Dasher front turn signal bulbs use P21W or 1157 size, while rear turn signal bulbs use 1156 size. The replacement chart covers 1974 through 1981 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 Dasher uses three distinct bulb types across its front and rear turn signal positions: P21W, 1157, and 1156.
The 1156 bulb is the most consistently used type in these specifications, appearing in the rear turn signal position across all eight model years from 1974-1981.
The 1156 follows the ANSI standard used in the US and Canada. It is a single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base.
The front turn signal of the Volkswagen Dasher shifted from the ANSI-standard 1157 bulb to the ECE-standard P21W between the 1976 and 1978 model years.
The P21W is an ECE-standard bulb used in European and worldwide markets. It is a single-filament signalling bulb rated at 12V and 21W, also fitted with a BA15s bayonet base.
The 1157 is an ANSI-standard dual-filament bulb rated at 12V with a 21W main filament and a 5W secondary filament, fitted with a BAY15d bayonet base. Its dual-filament design distinguishes it from both the 1156 and P21W.
Although the P21W and 1156 share the same BA15s bayonet base and identical 12V, 21W ratings, the P21W follows ECE standards while the 1156 follows ANSI standards, and the two are not confirmed as interchangeable within these specifications.
The 1157 uses a BAY15d base, which differs from the BA15s base found on both the 1156 and P21W. The BAY15d base includes offset pins to prevent incorrect single-filament bulbs from being seated in a dual-filament socket.