Rolls-Royce Silver Shadow II Turn Signal Bulb Size
The Rolls-Royce Silver Shadow II front and rear turn signal bulbs utilize a 1159 or P21W size. The replacement chart covers 1977 to 1980 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 Rolls-Royce Silver Shadow II uses two distinct bulb standards across its front and rear turn signal positions: the 1159, an ANSI-standard type common in North American markets, and the P21W, an ECE-standard type used in European and worldwide applications.
The P21W is a single-filament signalling bulb rated at 12V and 21W, fitted with a BA15s bayonet base. The BA15s designation indicates a single-contact base with a 15mm collar, which is not interchangeable with dual-contact bayonet bases.
The 1159 is a dual-filament bulb operating at 12V, fitted with a BAY15d bayonet base. The BAY15d base features offset pins to prevent incorrect insertion, and its dual-filament design distinguishes it functionally from the single-filament P21W despite both operating at 12V.
Because the BA15s and BAY15d bases differ in both pin count and pin alignment, the P21W and 1159 bulbs are not physically interchangeable, even though both operate at 12V.
In the Rolls-Royce Silver Shadow II, the front turn signal position used the P21W for 1977-1979 but shifted to the 1159 for the 1980 model year.
The rear turn signal position in the Silver Shadow II used the 1159 exclusively for the 1979 model year, while the P21W was fitted for 1977-1978 and again for 1980.
The front and rear turn signal positions do not share the same bulb type in every model year. For 1979, the front uses the P21W while the rear uses the 1159, and for 1980, the front uses the 1159 while the rear uses the P21W.