The Land Rover Range Rover brake light utilizes P21/5W and P21W bulb sizes for the lighting components. Data for the specified vehicle covers a range from 1987 through 2009.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The P21/5W is the most frequently specified bulb across the Land Rover Range Rover brake light data, covering the 1987-1988 and 2003-2009 model years for the standard brake light position.
The P21/5W operates on a dual-filament design rated at 12V with a 21W primary filament and a 5W secondary filament, mounted on a BAY15d bayonet base. The offset pins of the BAY15d base ensure the bulb can only be inserted in one orientation, preventing filament misassignment.
The P21W is a single-filament bulb rated at 12V and 21W, using a BA15s bayonet base with symmetrical pins. It is specified for the standard brake light position on the Range Rover across the 1994 and 1996-2002 model years.
Because the P21W and P21/5W share a similar physical form but use different base types, BA15s and BAY15d respectively, the two bulbs are not interchangeable. Substituting one for the other in a Range Rover application is not possible without modification to the socket.
The center high mount stop light on the Land Rover Range Rover uses the P21W for the 1987-1988, 1994, 1997, 1999, 2001, and 2002 model years.
The 12961 is a Philips part number designating a T10 miniature wedge bulb rated at 12V and 5W, using a W2.1x9.5d wedge base. It is specified for the Range Rover center high mount stop light in the 1996, 1998, and 2000 model years.
The T10 wedge base of the 12961 is physically and electrically distinct from the bayonet bases used by the P21W and P21/5W, making the 12961 incompatible with sockets designed for either of those bulb types.
The center high mount stop light position on the Range Rover alternates between the P21W and the 12961 across certain model years, indicating that the socket type in that position is not uniform across the production run covered by these specifications.