The White WHL front and rear turn signal bulbs utilize either 1157 or 2057 bulb sizes. The replacement chart covers 1981 through 1988 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 two bulb types specified for the White WHL are the 1157 and 2057, both of which are ANSI-standardized dual-filament bulbs used in the United States and Canada. Each uses a BAY15d bayonet base and operates at 12 volts.
The BAY15d bayonet base is a two-pin offset design. The offset pin placement is what physically distinguishes it from single-filament bayonet bases and prevents incorrect installation.
The 1157 bulb carries a 21W/5W filament rating, where the higher wattage serves the turn signal function and the lower wattage serves the running light function.
The 2057 bulb carries a 26.9W/8W filament rating. Both figures are higher than those of the 1157, making the 2057 the brighter of the two types across both filaments.
Although the 1157 and 2057 share the same BAY15d base and are physically interchangeable in terms of socket fit, their wattage outputs differ. Substituting one for the other may affect light output intensity.
The White WHL (1981-1987) takes a 2057 bulb in both the front and rear turn signal positions, with the specification applying to non-Conventional configurations.
The 1988 White WHL uses the 1157 bulb in both the front and rear turn signal positions, representing a change from the 2057 used in prior model years.