The Jeep FC170 front and rear turn signal bulbs use 1034 or 1154 size specifications. The replacement chart covers 1957 to 1966 production years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Jeep FC170 uses two distinct bulb types across its turn signal positions: the 1034 and the 1154, both of which are dual-filament bulbs sharing the BAY15d bayonet base.
The BAY15d base is an offset twin-contact bayonet fitting, which physically separates the two filaments to prevent incorrect installation and ensure polarity-dependent functions such as running light and turn signal operate independently.
Both the 1034 and 1154 are ANSI-standardized bulbs recognized in the US and Canada, and both are described as variants of the 1157, a widely used automotive bulb type.
The 1034 bulb is rated at 12V with a 21/5W dual-filament output, where the higher wattage filament serves the turn signal function and the lower wattage filament serves a secondary purpose such as a running or parking light.
The 1154 bulb differs from the 1034 in that it carries a 6V/12V voltage rating, indicating compatibility across two voltage systems, which reflects its status as an older variant associated with earlier automotive electrical standards.
The 1966 Jeep FC170 uses the 1034 bulb for both front and rear turn signals, while the 1957 model uses the 1154 bulb in both positions, meaning the front and rear positions are matched within each model year.
Although the 1034 and 1154 share the same BAY15d base type, they are not listed as interchangeable within these specifications, and the voltage difference between the two bulbs is a relevant factor in that distinction.