The Isuzu FVR front side marker bulb uses 168 or 89 size bulbs, while the rear side marker bulb uses 89 size bulbs. The replacement chart covers vehicle production from 1988 to 2011 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 Isuzu FVR front side marker position uses the 168 bulb across two distinct body configurations: the Tilt Cab variant for 2006-2011 and the Heavy Duty variant for 1995-2001.
The 168 is a T10 miniature wedge bulb rated at 12V and 4.9W, conforming to ANSI standards recognized in both the United States and Canada.
The wedge base design of the 168 bulb means it is retained by friction rather than a locking mechanism, requiring no rotation during installation or removal.
The 89 bulb is a single-filament type with a BA15s bayonet base, rated at 12V and 13W, and is also an ANSI-standard part recognized in the United States and Canada.
At 13W, the 89 bulb draws considerably more power than the 4.9W 168, reflecting its classification as a lower wattage variant of the 1156 bulb family rather than a direct equivalent.
The BA15s bayonet base of the 89 bulb is a single-contact fitting, distinguishing it from the dual-contact BA15d base found on some other bayonet-style automotive bulbs.
The Isuzu FVR Heavy Duty front side marker used the 89 bulb for 1988-1994, then transitioned to the 168 bulb starting in 1995, indicating a socket and base type change between those model years.
Because the 168 and 89 bulbs use physically incompatible base types, a wedge socket and a bayonet socket respectively, the two are not interchangeable without modification to the housing.
The rear side marker on the Isuzu FVR is specified only for the Heavy Duty configuration across 1988-1992 and 1994, with the 89 bulb applying to all listed rear side marker positions.
The front and rear side marker positions share the same 89 bulb specification for the Heavy Duty configuration years in which both positions are listed, meaning a single bulb type served both locations on those vehicles.