The Hino GC17 front and rear turn signal bulbs both utilize a 1156 size. The replacement chart covers 1990 to 1991 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1156 is the sole bulb type across all listed turn signal positions on the Hino GC17, appearing in both the 1990-1991 model years for front and rear applications.
The 1156 is an ANSI-standardized bulb recognized across the United States and Canada, meaning it conforms to a defined set of electrical and physical parameters shared by compliant manufacturers.
As a single-filament bulb, the 1156 serves one switching function per unit, which is consistent with its dedicated turn signal role rather than a combined stop/turn application.
The 1156 uses a BA15s bayonet base, where "BA15s" denotes a bayonet cap with a 15mm collar and a single contact pin, distinguishing it from the dual-pin BA15d variant used in other bulb types.
The 1156 operates at 12 volts, aligning with the standard automotive electrical system voltage found in light commercial vehicles of that era.
At 21 watts, the 1156 produces a power draw consistent with turn signal visibility requirements, and this wattage is a factor in the flash rate produced by the vehicle's turn signal relay.
The front and rear turn signal positions on the Hino GC17 share the same 1156 specification for 1990-1991, meaning a single bulb type services all four turn signal sockets on the vehicle.
Substituting a bulb with a dual-filament base such as the 1157, which uses a BA15d fitting, would be physically incompatible with the BA15s socket used by the 1156.