Chevrolet Silverado Side Marker Bulb Size

Additional Notes

• The 7443 bulb is the most frequently specified size across the Chevrolet Silverado side marker positions covered in these specifications. It is a dual-filament T20 wedge bulb rated at 12V with a 21W high filament and 5W low filament, conforming to ANSI standards for the US and Canadian markets.
• The 4157NA bulb appears across multiple front side marker positions for the Silverado 1500 and 2500/3500 HD trims from 2008-2014. It is a natural amber glass, dual-filament T25 wedge bulb rated at 12V, 27W/7W, with the amber tint built into the glass rather than applied as a coating.
• The 194 and 194NA bulbs share identical electrical ratings of 12V and 3.78W and the same T10 miniature wedge form, but the 194NA variant incorporates natural amber glass. These two types are not interchangeable in positions where amber output is required by the vehicle design, despite their otherwise identical construction.
• The 5702AK, specified for the 2012 Silverado 2500/3500 HD front side marker, is a Sylvania-branded variant of the ANSI 3157 bulb with an amber coating applied externally. Its electrical characteristics of 12V, 27W/7W match those of the 4157NA, though the two are distinct part numbers with different amber treatments.
• The Silverado 1500 and 2500/3500 HD trims frequently require different bulb sizes for the same model year and position. In 2014, for example, the front side marker takes a 4157NA on the 2500/3500 HD and a 7443 on the 1500, making trim-level confirmation necessary before selecting a replacement.
• For the 2016-2018 Silverado 1500 front side marker, the 7443 bulb is specified only for vehicles equipped with HID headlamps. This indicates the bulb fitment is tied to the headlamp package rather than the model year or trim level alone.
• The PC161 and PC195 bulbs are T10 miniature wedge types with a printed circuit board twist-lock socket, a mounting interface associated with instrument cluster applications. Their presence in rear side marker positions on certain Silverado 1500 and 2500/3500 HD configurations from 1999-2007 reflects a socket design specific to those assemblies and incompatible with standard wedge-base sockets.
• The 12961, specified for the 2012 Silverado 2500/3500 HD rear side marker on the rear fender with dual rear wheels, is a Philips part number for a T10 wedge bulb with a W2.1x9.5d base rated at 12V, 5W. Its lower wattage relative to the 4157NA and 7443 bulbs reflects its single-filament construction.
• In 2020, the front and rear side marker bulb assignments for the Silverado 1500 and 2500/3500 HD are reversed relative to each other. The front uses a 7443 on the 2500/3500 HD, while the rear uses a 7443 on the 1500 and a 194 on the 2500/3500 HD, meaning no single bulb size covers all four positions across both trims in that year.
• The 194 bulb, a clear T10 miniature wedge rated at 12V and 3.78W, is listed for both front and rear side marker positions on the Silverado across model years 2002-2006. It shares its physical form and electrical rating with the 194NA but lacks the amber glass, making the two visually distinguishable despite identical wattage and base type.