Triumph LC Rear Light & Indicator Wiring Adapter + AUX – Plug & Play

5.0/5 · 1 review

Connect any aftermarket rear light, indicators and AUX 12V output to your Triumph LC with this plug & play wiring adapter. No cutting, no splicing, original wiring untouched.

Bonvent Motorbikes

Plug & Play Rear Lighting Harness for Triumph Bonneville, Street Twin & Thruxton

Product overview

This Bonvent wiring adapter is designed to upgrade the rear lighting setup on Triumph liquid-cooled Modern Classics without cutting, splicing or modifying the original wiring loom.

It allows you to connect any aftermarket tail light, brake light, license plate light, two rear turn signals and an auxiliary 12V output while keeping the original Triumph connectors untouched.

The adapter uses thick, high-quality sleeving for a clean and durable finish. It is ideal for tail tidy installations, custom rear light conversions and compact rear indicator setups.

An inline diode is integrated into the Bonvent wiring adapter loom to help prevent ECU warning lights when fitting non-Triumph rear lights.

Compatibility

This wiring adapter is compatible with the following Triumph liquid-cooled Modern Classic models.

Euro 4 and Euro 5 compatible models:

Triumph Street Twin
Triumph Street Cup
Triumph Bonneville T100
Triumph Bonneville T120
Triumph Thruxton R
Triumph Thruxton S
Triumph Street Scrambler

Euro 4 only:

Triumph Speed Twin 1200, 2019–2020

Not compatible with

Triumph Bobber
Triumph Speedmaster
Triumph Speed Twin Euro 5 models

If you are unsure about your motorcycle year or rear wiring configuration, please check compatibility before ordering.

Key features

Plug & play installation: connects directly to the original Triumph rear wiring connectors.
No cutting or splicing: the original wiring harness stays untouched.
Integrated inline diode: helps prevent ECU warning lights when fitting non-Triumph rear lights.
Rear light and indicator output: tail light, brake light, license plate light and two rear indicators.
AUX 12V output: additional auxiliary power output for extra lighting accessories.
Thick high-quality sleeving: clean, durable and premium finish.
Reversible modification: easy to remove if you want to return the motorcycle to its original configuration.

Wiring color code

TL — Tail light + license plate light
- Red: brake light — double bullet 3.5 mm connector
- Green: tail light + license plate light — double bullet 3.5 mm connector
- Black: ground — double bullet 3.5 mm connector
TS-L — Left turn signal
- Blue: left-hand side signal — bullet 3.5 mm connector
- Black: ground — bullet 3.5 mm connector
TS-R — Right turn signal
- Orange: right-hand side signal — bullet 3.5 mm connector
- Black: ground — bullet 3.5 mm connector
AUX — 12V auxiliary power
- Yellow: 12V auxiliary power — bullet 3.5 mm connector
- Black: ground — bullet 3.5 mm connector

Specifications

Length: 49 cm
Harness type: rear light, brake light, license plate light, AUX and two rear indicators
Connector type: bullet 3.5 mm outputs
Installation: plug & play
Modification required: no cutting, no splicing, no soldering
Sleeving: thick high-quality protective sleeving
Integrated component: inline diode to help prevent ECU warning lights

Product guide

Clean Triumph Rear Lighting Upgrades Without Cutting the Original Wiring

When installing an aftermarket rear light, tail tidy, license plate light or rear indicators on a Triumph liquid-cooled Modern Classic, keeping the original wiring untouched is the cleanest solution.

This Bonvent plug & play rear wiring adapter gives you dedicated outputs for the tail light, brake light, license plate light, left and right rear turn signals, plus an AUX 12V output. It allows a clean custom installation without cutting, splicing or soldering the original Triumph wiring loom.

The harness uses 3.5 mm bullet connectors, thick high-quality sleeving and an integrated inline diode to help prevent ECU warning lights when fitting non-Triumph rear lights.

Designed for Triumph Bonneville, Street Twin, Street Cup, Thruxton and Street Scrambler custom builds, this adapter makes rear lighting upgrades cleaner, easier and reversible.

Customer proof

Customer Reviews for T120/T100 Triumph Wiring Adapter

Every Bonvent part is designed to bring more character and enjoyment to a rider’s project. Our greatest reward is a satisfied customer and a growing community, which is why we aim for excellence in every detail.

5.0

Average rating Based on 1 review

All 1 review

Super usefull and amazing quality

Bonvent Motorbikes replied Jul 17, 2026

Thank you, Jeremy, for taking the time to share your feedback. We’re really pleased that you found the wiring adapter both useful and well made. It is a small part, but it can make the installation much cleaner and easier :)

FAQ

Does this adapter require cutting the original Triumph wiring?

No. This adapter is plug & play and connects to the original Triumph rear wiring connectors. No cutting, splicing or soldering is required.

What can I connect with this wiring adapter?

You can connect an aftermarket rear light, brake light, license plate light, left and right rear turn signals, plus an AUX 12V output for additional lighting accessories.

What type of connectors does it use?

The adapter uses 3.5 mm bullet connectors for the rear light, indicators and AUX output.

Why is there an inline diode?

The integrated inline diode helps prevent ECU warning lights when fitting non-Triumph rear lights.

Is the adapter reversible?

Yes. Because the original wiring loom is not cut or modified, the adapter can be removed if you want to return the motorcycle to its original wiring setup.

Which Triumph models are compatible?

This adapter fits Euro 4 and Euro 5 versions of the Triumph Street Twin, Street Cup, Bonneville T100, Bonneville T120, Thruxton R, Thruxton S and Street Scrambler. It also fits the Euro 4 Speed Twin 1200 from 2019 to 2020.

Does it fit the Triumph Bobber or Speedmaster?

No. This adapter is not compatible with the Triumph Bobber or Triumph Speedmaster.

Does it fit Euro 5 Speed Twin models?

No. This adapter is not compatible with Euro 5 Speed Twin models.