Wiring trailer lights correctly keeps you legal and safe on Australian roads. This guide shows how to wire LED trailer lights, tail lights, brake lights and side lights, how to test them, and what to use on marine trailers. If you would rather not tackle the job yourself, Martin’s Trailer Parts in Perth can supply complete trailer lights kits and wiring, or help you choose the right parts at Bayswater, O’Connor or Wangara. For quick advice email sales@trailerparts.net.au.
What You Need Before You Start
A trailer lights kit that suits your trailer
A trailer lights wiring harness and plug to match your tow vehicle
Crimp connectors or solder and heat shrink
Wire stripper, crimping tool, electrical tape and cable ties
Multimeter or test lamp
Rust-free mounting hardware and a clean earth point
For boat trailers, submersible trailer lights and marine grade heat-shrink connectors
Australian Trailer Light Wiring Colours
Common colour codes
Brown for tail or park lights
Yellow for left indicator
Green for right indicator
Red for brake lights
White for earth or ground
Blue for auxiliary or electric brakes if fitted
Always confirm with your kit instructions, as brands can vary.
Prepare The Trailer For Wiring
Mount lights and plan cable runs
Position tail lights, brake lights and side markers as per the kit instructions so they are visible and protected.
Lay out the wiring harness along the inside of the chassis rails. Avoid sharp edges, pinch points and hot areas near exhausts.
Fix the loom with clips or cable ties at regular intervals to prevent chafing.
Connect Tail And Brake Lights
Make the core connections
Brown wire to tail or park lights on both sides.
Red wire to brake light terminal.
White wire firmly earthed to bare metal on the trailer frame. Clean paint and rust from the contact point.
Use heat-shrink connectors or heat-shrink over crimp joins for a durable seal.
Wire Indicators And Side Lights
Indicators
Yellow to the left indicator, green to the right indicator. Keep joins neat and supported to prevent vibration damage.
Side lights and number plate light
Piggyback side lights into the tail light circuit for constant night visibility.
If your kit includes a number plate light, connect it to the tail light feed.
Marine And Submersible Trailer Lights
Keep water out
Choose fully sealed submersible trailer lights and marine rated cabling.
Route wiring high along the chassis where possible and create drip loops before each light.
Seal joins with adhesive-lined heat-shrink and dielectric grease to resist corrosion.
After launching, rinse lights and wiring with fresh water to extend life.
Test All Functions Before You Tow
What to check
Tail lights illuminate with headlights or parkers.
Brake lights activate cleanly when the pedal is pressed.
Left and right indicators flash at the correct rate.
Reverse lights or auxiliary functions work if fitted.
If a circuit fails, first recheck the earth point and plug connection. Poor earths cause most faults.
Troubleshooting Common Issues
No tail or brake lights
Inspect fuse and vehicle plug. Confirm brown and red feeds have power with a multimeter.
Fast flashing indicators
Usually a bad earth or a blown globe in non LED setups. Confirm yellow or green feeds and the white earth.
Intermittent operation
Look for crushed wiring under U bolts, loose crimp joins, or moisture inside non sealed lights.
Safety And Compliance Tips
Use ADR compliant trailer lights and plugs that match your vehicle.
Secure wiring every 200 to 300 mm to prevent chafe.
Keep a spare plug, fuses and a basic test lamp in the vehicle.
Record the wiring colours and layout inside the trailer toolbox for future repairs.
When To Ask For Help
If auto electrical work is not your thing, or your trailer has electric brakes, our team can recommend a complete trailer lights kit or pre wired options. Visit Martin’s Trailer Parts in Bayswater, O’Connor or Wangara, or email sales@trailerparts.net.au for friendly advice.
Get The Right Trailer Lights Kit In Perth
For a reliable trailer lights kit, LED upgrades or submersible marine lights, drop into your nearest store or contact sales@trailerparts.net.au. We will help you choose the best kit for your trailer and set you up with everything needed to wire it safely