The 1156 is the sole bulb type listed across all turn signal positions in the Volvo WH specifications, appearing in both the front and rear turn signal applications for 1996-1997.
The 1156 is a single-filament bulb, meaning it serves one lighting function only, which is consistent with its use in dedicated turn signal circuits rather than combined stop/turn applications.
The 1156 operates at 12 volts and draws 21 watts, placing it in the standard incandescent range for automotive turn signal use.
The 1156 uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin, distinguishing it from the dual-contact BA15d base used on other bulb types.
The 1156 conforms to ANSI standards and carries recognition in both the United States and Canada, indicating it meets North American automotive lighting requirements.
The front and rear turn signal positions on the Volvo WH for 1996-1997 share the same 1156 bulb specification, meaning the same bulb type is interchangeable between both locations on the vehicle.
The BA15s bayonet base is not interchangeable with the BA15d base despite the two sharing the same 15mm collar width, as the pin configurations differ and a dual-contact bulb cannot seat correctly in a single-contact socket.