American Motors Hornet Back Up Light Bulb Size

Additional Notes

• The 1156 is the sole bulb type listed for the back up lights of the American Motors Hornet across all model years covered in the specifications, spanning 1970-1977.
• The 1156 is an ANSI-standardized bulb, meaning its physical and electrical characteristics conform to a defined North American standard recognized in both the United States and Canada.
• The 1156 operates on a 12-volt electrical system and draws 21 watts, which is typical for incandescent reverse lighting applications of that era.
• The bulb uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin, distinguishing it from the dual-contact BA15d variant.
• Because the 1156 is a single-filament bulb, it serves one dedicated lighting function, as opposed to dual-filament types that handle two functions such as braking and running light within one housing.
• The BA15s bayonet mount is a twist-and-lock style base, where the bulb is inserted and rotated to secure it, rather than threaded into place.
• The consistent use of the 1156 across all eight model years indicates no bulb specification change occurred within the 1970-1977 production run of the Hornet as reflected in these records.
• The 1156 bulb type is widely used across many vehicle makes and applications, which generally means broad availability as a replacement part, though fitment to a specific housing depends on the socket design of the vehicle.