Saab 9-3 Turn Signal Bulb Size

Additional Notes

• PY21W is the most frequently specified bulb across the Saab 9-3 turn signal data. It is an ECE-standard single-filament amber bulb rated at 12V and 21W, fitted with a BAU15s bayonet base. The amber coloring is built into the glass envelope rather than achieved through a lens or coating.
• The BAU15s base of the PY21W is offset, meaning the two pins are positioned at different heights around the base. This distinguishes it physically from the BA15s base used on the P21W, and the two bulbs are not interchangeable despite sharing the same 21W rating and general form.
• The 12496 is a Philips/Osram part number for a 12V halogen bulb used in specialty applications. It appears across both the Front Inner Turn Signal and Rear Turn Signal positions on the Saab 9-3, covering multiple model years in each location.
• The P21W, specified for the Front Turn Signal on the 2010-2011 Saab 9-3, uses a BA15s bayonet base. Unlike the PY21W, its glass envelope is clear, with amber output dependent on the vehicle's lens. Substituting a P21W for a PY21W, or vice versa, would result in a base incompatibility.
• The 1157NA and 1034NA bulbs, both ANSI-standard dual-filament types with BAY15d bases, are specified only for the Front Inner Turn Signal position on the 1999-2002 models. The dual-filament design means a single bulb serves two brightness levels, typically for combined stop and turn functions.
• The 1034NA is noted as a variant of the 1157NA, sharing the same BAY15d base and 12V/21W/5W ratings. The two types are listed for different model years within the same position, which reflects a manufacturer substitution rather than a structural change in the lamp housing.
• The 12961 is a miniature wedge bulb with a W2.1x9.5d base, rated at 12V and 5W. Its low wattage places it well below the other turn signal bulbs in the specifications, consistent with its use in the Front Outer Turn Signal position on 1999-2002 models rather than as a primary signaling source.
• The Front Turn Signal position on the Saab 9-3 uses PY21W across 1999-2007, then transitions to 12496 for 2008-2009, and then to P21W for 2010-2011. These shifts reflect changes in lamp assembly design across the 9-3's production generations rather than simple bulb substitutions.
• The Rear Turn Signal position shows alternating bulb types across consecutive years, with PY21W and 12496 appearing in non-sequential patterns between 1999 and 2011. This indicates that different trim levels or regional variants within the same model year may have used different lamp assemblies.
• The Front Inner Turn Signal position, present only on 1999-2007 models, uses three distinct bulb types across that span. Its absence from 2008 onward, alongside the continued presence of a Front Turn Signal entry, suggests a consolidation of front lamp assemblies in later production years.