Triumph Bonneville T120 Turn Signal Bulb Size

The Triumph Bonneville T120 front turn signal requires 232 or 5008 bulb sizes, while the rear turn signal uses a 232 bulb size. The replacement chart covers 2016 to 2018 vehicle 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.

Front Turn Signal

Years	Bulb Type	Shop
2017-2018	232	Check Price
2016	5008	Check Price

Rear Turn Signal

Years	Bulb Type	Shop
2016-2018	232	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Festoon bulb with SV8.5 base. 12V, 3W.	232	Check Price
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V.	5008	Check Price

Other Locations

Additional Notes

The 232 bulb follows the ANSI standard for the US and Canadian markets. It is a festoon-type bulb, meaning it is cylindrical in shape with end caps that seat into spring-loaded holders rather than a twist or plug-in base. It operates on 12 volts and draws 3 watts.
The 232 bulb uses an SV8.5 base, a designation that refers to the spacing between its two end contacts. This base type is specific to festoon configurations and is not interchangeable with bayonet or wedge base bulbs.
The 5008 bulb also conforms to the ANSI standard for the US and Canadian markets. It is a single-filament bulb with a BA15s bayonet base, which uses a single locating pin to secure the bulb into its socket with a push-and-twist motion.
The 5008 is described as a lower wattage variant of the 1156 bulb. While it shares the BA15s bayonet base with the 1156, the difference in wattage means the two are not direct substitutes in applications where wattage is a factor.
On the Triumph Bonneville T120, the front turn signal position uses two different bulb types across the 2016-2018 model years. The 2016 model year uses the 5008, while the 2017-2018 model years use the 232.
The rear turn signal position on the Bonneville T120 uses the 232 bulb across all three model years covered, spanning 2016-2018.
Because the front turn signal changed from a BA15s bayonet base (5008) to an SV8.5 festoon base (232) between the 2016 and 2017 model years, the socket type in the front housing differs between those years, and bulbs are not interchangeable between them.