The 1034 and 1154 bulbs are the two turn signal bulb types specified for the Ford Skyliner across its production years.
Both the 1034 and 1154 are ANSI-standard dual-filament bulbs sharing the BAY15d bayonet base, which is a two-pin offset base designed to prevent incorrect installation.
The 1034 bulb operates at 12V with a 21/5W dual-filament rating, where the higher wattage filament serves the turn signal function and the lower wattage filament serves a secondary function such as running light duty.
The 1154 bulb is rated for both 6V and 12V operation, reflecting its origin in an era when automotive electrical systems were transitioning between those two voltages.
Both the 1034 and 1154 are described as variants of the 1157 bulb, meaning they share the same BAY15d base but differ in voltage or wattage characteristics from that more widely known type.
The Ford Skyliner used the 1154 bulb for both front and rear turn signals during the 1954-1955 model years.
Starting with the 1956 model year, the Ford Skyliner transitioned to the 1034 bulb for both front and rear turn signals, a specification that remained consistent through 1959.
Because the 1034 and 1154 share the same BAY15d base, physical fitment between the two types is possible, but their differing voltage ratings make them non-interchangeable without consideration of the vehicle's electrical system voltage.