The Rover 3500S front and rear turn signal bulbs both utilize a 1156 size bulb for proper operation. The replacement chart covers vehicle production spanning 1969 to 1971.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1156 is the sole bulb type listed across all turn signal positions for the Rover 3500S, covering both front and rear applications for the 1969-1971 model years.
The 1156 is a single-filament bulb, meaning it serves one electrical function only, which in this context is turn signaling rather than a combined stop and turn signal role.
The 1156 operates at 12 volts and draws 21 watts, placing it in the standard range for automotive turn signal applications of that era.
The 1156 uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin, as opposed to the dual-contact BA15d variant used in some other bulb types.
The 1156 conforms to ANSI standards and is rated for use in the United States and Canada, reflecting a standardized specification rather than a proprietary or regional-only fitment.
Because the front and rear turn signal positions on the Rover 3500S share the same 1156 specification across all listed years, the bulbs are interchangeable between those positions within the same vehicle.
The BA15s base of the 1156 is not compatible with BA15d sockets, so substituting a dual-contact bulb of similar wattage would not be a correct fitment for the Rover 3500S turn signal housings.