Nissan 620 front turn signal bulbs use 1157 size while rear turn signal bulbs use 1073 or P21W size. The replacement chart covers 1975 to 1979 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Nissan 620 front turn signal uses the 1157 bulb across all listed model years, 1975-1979.
The 1157 is a dual-filament bulb operating at 12V with a 21W main filament and a 5W secondary filament, mounted on a BAY15d bayonet base.
The BAY15d base features offset pins, which physically prevents single-filament bulbs from being seated in sockets designed for dual-filament applications.
The Nissan 620 rear turn signal does not follow a single bulb type across its listed model years, with the 1073 specified for 1976 and 1979, and the P21W specified for 1975, 1977, and 1978.
The 1073 and P21W share the same BA15s bayonet base, meaning the two bulbs are physically interchangeable at the socket level.
Despite sharing a base type, the 1073 and P21W differ in wattage. The 1073 operates at 13W while the P21W operates at 21W, which can affect brightness and may influence turn signal flash rate depending on the vehicle's flasher relay tolerance.
The 1073 follows the ANSI standard used in the United States and Canada, while the P21W follows the ECE standard used in Europe and other international markets.
The 1073 is classified as a lower wattage variant of the 1156, sharing the same BA15s single-filament configuration but drawing less power.
The P21W, at 21W, matches the wattage of the 1157's primary filament, though it is a single-filament bulb and is not a substitute for dual-filament applications such as the front turn signal position on the Nissan 620.