The Sterling 825 brake light requires 1156 and P21W bulb sizes for the specific lighting components located at the rear of the vehicle. Data for the bulb sizes covers the range from 1987 to 1988.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1156 is an ANSI-standardized bulb used across both the brake lights and the center high mount stop light of the Sterling 825 for the 1987-1988 model years.
The 1156 operates at 12 volts and 21 watts, placing it in the standard range for single-circuit stop light applications in passenger vehicles.
As a single-filament bulb, the 1156 serves only one electrical function per socket, which is consistent with its use in dedicated brake and stop light positions rather than combined tail/stop applications.
The 1156 uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin offset to one side, ensuring the bulb seats in only one rotational position.
The BA15s base is not interchangeable with the BA15d base, which carries two offset pins for dual-filament bulbs such as the 1157. Substituting one for the other is not physically possible without modification.
The 1156 is recognized under both US and Canadian ANSI standards, indicating consistent specification requirements across both markets for the Sterling 825.
The same bulb size, 1156, applies uniformly to all brake light positions on the Sterling 825, including the center high mount stop light, across both model years covered in the specifications.