Ford Courier front turn signal bulbs utilize 1034NA, 1157NA, or 1157 bulb sizes, while rear turn signal bulbs require the 1157 size. The replacement chart covers 1972 through 1982 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 1157 bulb is the most prevalent type across these specifications, serving as the rear turn signal fitment for all Ford Courier model years from 1972-1982 and as the front turn signal fitment for several years within that same range.
All three bulb types listed in these specifications, the 1157, 1157NA, and 1034NA, share the BAY15d bayonet base and operate at 12V with a dual-filament 21W/5W configuration, making them electrically equivalent.
The BAY15d bayonet base is a two-pin offset base design where the two pins are positioned at different heights, which prevents incorrect installation by ensuring the bulb can only be seated in one orientation.
The dual-filament design of these bulbs serves two functions within a single housing, with the higher-wattage filament (21W) handling the turn signal flash and the lower-wattage filament (5W) serving as a running or parking light.
The 1034NA is described as a variant of the 1157, with the key distinction being its natural amber glass envelope, which produces amber light output without relying on a colored lens.
The 1157NA shares the same natural amber glass characteristic as the 1034NA, differentiating both "NA" suffix bulbs from the clear-glass standard 1157.
For the Ford Courier front turn signal, the specified bulb alternates between the 1034NA and 1157NA across certain model years, both of which carry the natural amber designation despite being distinct part numbers.
Because the 1157, 1157NA, and 1034NA all use the BAY15d base and identical voltage and wattage ratings, physical interchangeability is present, though the amber glass variants will affect light color output when used with a clear lens.