Mercury LN7 front and rear turn signal bulbs both utilize a 1157 size bulb for proper operation. The replacement chart covers 1982 to 1983 model years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1157 is the sole bulb type specified for the Mercury LN7 across all listed turn signal positions and model years.
The 1157 is a dual-filament bulb, meaning it serves two distinct lighting functions within a single unit, typically combining a higher-wattage filament for active signaling and a lower-wattage filament for a running or parking light function.
The 1157 operates at 12 volts with a wattage rating of 21W for the primary filament and 5W for the secondary filament.
The 1157 uses a BAY15d bayonet base, which is an offset dual-contact base designed to ensure the bulb is inserted in only one orientation, preventing incorrect filament alignment.
The 1157 conforms to ANSI standards and is recognized in both the United States and Canada, reflecting a standardized specification shared across North American markets.
The 1157 specification applies to both the front and rear turn signal positions on the Mercury LN7 for the 1982-1983 model years.
Because the front and rear turn signals share the same bulb type, a single 1157 bulb serves as a direct replacement across all four turn signal positions on the vehicle.
The BAY15d base of the 1157 is not interchangeable with single-filament bayonet bases such as the BA15s, and substituting a single-filament bulb would result in the loss of one lighting function.