Ford F-600 front side marker bulbs use 194 or 97 size, while rear side marker bulbs use 194, 168, or 97 bulb sizes across multiple production years. The replacement chart covers 1970 to 1994 model 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 Ford F-600 front side marker position uses the 194 bulb across 1971-1994, with the sole exception of the 1970 model year, which uses the 97 bulb instead.
The 194 is a T10 miniature wedge bulb rated at 12V and 3.78W, conforming to ANSI standards for the US and Canadian markets.
The 97 bulb differs fundamentally in its base design, using a BA15s single-contact bayonet mount rather than a wedge base. It is rated at 12V and 13W, making it a significantly higher-wattage lamp than either the 194 or 168.
The rear side marker position on the Ford F-600 uses three distinct bulb types across its production span, reflecting changes at specific model years.
The 168 bulb, like the 194, is a T10 miniature wedge type rated at 12V, though its wattage is 4.9W rather than 3.78W. The two bulbs share the same physical wedge base format but are not electrically identical.
The rear side marker position transitions from the 97 bayonet-base bulb in 1970-1973 to the 168 wedge bulb in 1974-1980, and then to the 194 wedge bulb from 1983 onward through 1994.
Because the 97 uses a BA15s bayonet base while the 194 and 168 use a wedge base, the 97 is not physically interchangeable with either of the other two bulb types without a socket adapter or housing modification.
The 194 and 168 share the T10 wedge base form factor, which means the socket type is the same, but substituting one for the other results in a wattage difference that may affect circuit load and lens brightness.
The 97 is noted as a variant of the 1156 bulb family, though it operates at a lower wattage than a standard 1156. This distinction is relevant when sourcing replacements, as a full 1156 is not a direct substitute.