Honda Motorcycle VT1100C2 Shadow ACE Turn Signal Bulb Size
Honda Motorcycle VT1100C2 Shadow ACE front turn signal bulbs measure 1034 in size, while rear turn signal bulbs measure P21W or 1073. The replacement chart contains bulb size specifications across 1995 to 1999 vehicle production years.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Honda Motorcycle VT1100C2 Shadow ACE uses the 1034 bulb across all front turn signal positions for the 1995-1999 model years.
The 1034 is an ANSI-standard dual-filament bulb rated at 12V and 21/5W, fitted with a BAY15d bayonet base, and is classified as a variant of the 1157.
A dual-filament design means the 1034 serves two lighting functions from a single housing, with the higher-wattage filament handling turn signaling and the lower-wattage filament handling a secondary function such as running or parking light duty.
The rear turn signal position does not share a single bulb type across the full 1995-1999 production span, with two distinct bulb types specified depending on the model year.
The 1995, 1996, and 1999 VT1100C2 Shadow ACE rear turn signals use the P21W, an ECE-standard single-filament bulb rated at 12V and 21W with a BA15s bayonet base.
The 1997-1998 rear turn signals use the 1073, an ANSI-standard single-filament bulb rated at 12V and 13W, also fitted with a BA15s bayonet base.
Although the P21W and 1073 share the same BA15s bayonet base, their wattage ratings differ substantially, at 21W and 13W respectively, which makes them non-interchangeable without affecting circuit load and signal timing.
The front 1034 bulb uses a BAY15d base, which is physically distinct from the BA15s base used by both rear turn signal bulbs, making front and rear bulbs incompatible with each other's sockets.
The BAY15d base features offset locating pins that prevent incorrect single-filament bulbs from being seated in a dual-filament socket, serving as a physical interchangeability safeguard.
The 1034 and P21W operate under different standardization systems, ANSI and ECE respectively, which reflects regional market differences in bulb classification rather than differences in base type or voltage.