Chevrolet Tiltmaster (W-Series) Turn Signal Bulb Size
Chevrolet Tiltmaster (W-Series) front and rear turn signal bulbs utilize 1157, 1156, and 1073 sizes depending on location and model variation. The replacement chart covers 1986 through 2001 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 Chevrolet Tiltmaster (W-Series) turn signal specifications cover two distinct bulb types across its production span: the dual-filament 1157 and the single-filament 1156, with the 1073 appearing in a limited rear application.
The 1157 is a dual-filament bulb rated at 12V with a 21W/5W output and a BAY15d bayonet base. The two filaments serve separate functions, with the higher-wattage filament handling the turn signal and the lower-wattage filament serving as a running or parking light.
The 1156 is a single-filament bulb rated at 12V and 21W with a BA15s bayonet base. Because it carries only one filament, it serves a single lighting function rather than the combined role of the 1157.
The BAY15d base of the 1157 and the BA15s base of the 1156 are physically incompatible. Although both use a 15mm bayonet fitting, the BAY15d has offset pins while the BA15s has aligned pins, making the two non-interchangeable.
The 1073 shares the BA15s bayonet base with the 1156 but operates at a lower wattage of 13W versus 21W. While the base type is physically the same, substituting a 1156 for a 1073 would introduce a higher current draw than the original specification.
The front turn signal on the Tiltmaster (W-Series) used the 1157 for model years 1986-1988 and again for 1997-2001, while the 1156 was specified for 1992-1996.
The rear turn signal specification shows greater variation across the production range. The 1157 was used in 1986-1988 and 1997-2001, the 1156 in 1992-1994, and the 1073 in 1995-1996.
The front and rear turn signal bulbs share the same specification for most model years, but 1995-1996 represents a notable divergence, with the front using the 1156 and the rear using the lower-wattage 1073.
All three bulb types in these specifications conform to ANSI standards applicable in both the United States and Canada, indicating standardized electrical and physical tolerances across the range.
The shift from 1156 to 1157 in the front turn signal position between the 1996 and 1997 model years reflects a change from a single-filament to a dual-filament configuration, which alters the socket type required.