Quick answer: On an Australian 7-pin flat trailer connection, Pin 3 is earth, Pin 5 is the service-brake circuit and Pin 6 operates the stop lamps. Connect by moulded terminal number, check the diagram’s viewing direction and test the required functions with the actual trailer.
This guide applies when your GWM Cannon towing setup uses an Australian 7-pin flat connection. Inspect the socket actually fitted: the vehicle name alone does not establish its connector format, harness or active circuits.
The focus is terminal identification, trailer-end plug replacement and functional checks. Vehicle-side harness connections and brake-controller installation require the instructions for your exact vehicle and equipment.
What is the Australian 7-pin flat trailer plug pinout?
Use the terminal assignments below for an Australian 7-pin flat connection. ADR 42/05 references AS 4177.5-2004 for the electrical connector; a European or American seven-pin connector can use a different format and circuit map.
| Pin | Wire colour | Circuit function |
|---|---|---|
| 1 | Yellow | Left indicator |
| 2 | Black | Reversing signal |
| 3 | White | Earth return |
| 4 | Green | Right indicator |
| 5 | Blue | Service brakes, where fitted |
| 6 | Red | Stop lamps |
| 7 | Brown | Tail, clearance and side-marker lamps |
References: Australian Government VSB1 Revision 6, August 2026, page 48 and ADR 42/05, section 21.
These colours identify the connector circuits. They do not establish the colour of every wire in the Cannon’s vehicle loom, and previous repairs may use different colours. Verify terminal numbers and circuit function before changing a connection.
Shared earth return
A poor return connection can affect several lamps together. Test its performance under load rather than relying only on an unloaded continuity check.
Brakes and stop lamps
Pin 5 serves the brake circuit; Pin 6 serves the stop lamps. Working brake lights do not demonstrate that electric trailer brakes operate.
Do not repurpose Pin 5 as a caravan power supply. VSB1 recommends reserving it for service brakes. A fridge or battery charger needs an auxiliary circuit and connector arrangement selected for its load.
Does the diagram show the mating face or the cable side?
A wiring diagram must identify both the connector and the viewing direction. Looking into its mating face gives a mirrored view of the cable-entry side; a plug drawing must also be distinguished from a socket drawing.
The table above maps terminal numbers to functions without prescribing a physical left-to-right sequence. Use the moulded numbers and your connector manufacturer’s labelled drawing to locate the terminals.
- Identify the component. Confirm whether you are working on the trailer plug or vehicle socket.
- Check the view label. Look for “mating face”, “terminal side” or “cable-entry side”.
- Match the orientation feature. Align the latch, lid or other feature shown in the drawing.
- Read the terminal numbers. Do not copy a colour sequence from an unlabelled image.
- Document the original wiring. Photograph it before disassembly, then verify its function instead of assuming it was correct.
How do you replace a damaged trailer-end plug?
First establish whether the plug is actually damaged. A new housing will not repair corroded copper further along the cable, a failed trailer lamp or a missing vehicle-side supply.
Prepare the correct equipment
- A replacement Australian 7-pin flat plug with a labelled terminal drawing.
- Terminals and preparation tools suitable for the conductor and connector.
- The connector’s strip-length, tightening and strain-relief instructions.
- Suitable circuit-testing equipment and access to the actual trailer.
Follow this installation sequence
- Isolate power. Disconnect the trailer from the vehicle. Isolate any trailer battery or other supply that could energise the affected wiring, following the equipment instructions.
- Inspect the cable. Check for corrosion, crushed insulation, heat damage and broken strands. Repair damaged wiring before fitting the new plug.
- Prepare the conductors. Strip only the length specified for the terminal. Keep strands intact and avoid exposed copper outside the contact.
- Connect by terminal number. Match each verified circuit to the numbered terminal. Follow the connector’s connection and tightening method.
- Secure the assembly. Fit the cable clamp and seals as instructed. Allow coupling movement while keeping the cable clear of the road, sharp edges and moving parts.
- Inspect and test. Check for loose contacts and stray strands before restoring power. Test the required functions individually, then under combined load.
A new vehicle-side harness is a separate installation. Confirm the VIN, build date, exact variant, existing tow package and required socket before ordering; do not connect into the rear loom using this trailer colour table alone.
Vehicle and trailer wiring must be appropriately supported and protected. See ADR 42/05, section 21 for wiring protection and routing requirements.
Which checks confirm the connection works?
Test with the actual trailer after installation. A small socket tester can identify missing signals, but may not reproduce the current demand or intermittent faults of the trailer you intend to tow.
| Check | Method | Expected result |
|---|---|---|
| Indicators | Operate left and right separately | The correct trailer side flashes without unintended lamp operation |
| Tail and stop lamps | Check each function, then operate them together | Both functions remain distinct without unexpected dimming or interaction |
| Reversing signal | Use a safe, stationary procedure where the circuit and lamps are fitted | The reversing lamps operate as intended |
| Earth return | Inspect connections and measure voltage drop while the lamps operate | The return path supports the working load without excessive voltage loss |
| Electric brakes | Follow the controller’s specified detection and functional test procedure | The controller detects and operates the compatible trailer brake system |
| Cable retention | Check plug engagement, strain relief and coupling movement | No pulling, snagging or intermittent connection |
Why can a multimeter reading be misleading?
A corroded connection may show voltage with no load but lose much of it when a lamp operates. Compare readings at the socket and load, and measure the voltage drop across suspect connections while the circuit is working.
Use DC voltage mode for powered checks and avoid bridging adjacent terminals. Resistance or continuity measurements require an isolated circuit; do not use those modes on live wiring.
Electric brake controllers can use pulsed outputs or require a detected load. Follow the controller’s test procedure rather than expecting a constant voltage at an unloaded Pin 5.
What should you check if a test fails?
- One lamp fails: check that lamp, its terminal and its individual circuit.
- Several lamps dim or interact: inspect the shared earth and test voltage drop under combined load.
- Stop lamps work but electric brakes do not: check controller status and the separate Pin 5 circuit using the controller instructions.
- Protection repeatedly trips: isolate the circuit and locate the fault before further use.
Do not tow with unresolved required lighting or brake faults. Never increase a fuse rating to hide a fault. Stop testing if wiring overheats, and have the affected circuit checked.
What do the plug checks tell you about the rest of the setup?
A working socket confirms only the functions you tested. It does not establish caravan charging capacity, vehicle trailer detection, parking-sensor behaviour or compatibility with every trailer brake system.
A lighting bypass module and a vehicle-integrated trailer module can perform different jobs. A “CAN-bus” label or plug-in connector alone does not establish coding requirements or retained vehicle functions.
For electric brake-controller installation, read our GWM Cannon brake controller guide alongside the exact controller manual. The component instructions govern cable sizing, protection, mounting and connection details.
When are replacement parts relevant?
Select parts after identifying the missing or failed function. A lighting harness does not replace an electric brake controller, and neither component repairs a loose trailer-end contact.
Vehicle-specific trailer wiring harness
An enquiry option when vehicle-side lighting wiring needs to be added or replaced. The default BYD Shark 6 configuration is not a Cannon fitment; request confirmation for your vehicle and Australian 7-pin flat socket.
Proportional electric brake controller
Relevant when a compatible controller is needed for electric trailer brakes. Confirm the brake type, axle configuration and supplied installation instructions before selecting it.
Send the VIN, build date, variant, country of registration and photos of the existing connections with a fitment enquiry. Include the trailer brake type and any auxiliary loads; a broad model-year range cannot establish the correct electrical configuration.
Frequently asked questions
What are the Australian 7-pin flat trailer plug colours?
Pin 1 is yellow, Pin 2 black, Pin 3 white, Pin 4 green, Pin 5 blue, Pin 6 red and Pin 7 brown. Match these to the moulded terminal numbers and verify circuit function, especially where wiring has been repaired.
Does this pinout identify the wires in my Cannon’s rear loom?
No. It identifies the Australian trailer connector circuits. Vehicle-side wire colours and connection points require the instructions for your exact Cannon and harness; do not splice into the vehicle loom using this table alone.
Should I read the plug diagram from the front or cable side?
Follow the view specified by the connector manufacturer. The mating face and cable-entry side are mirrored, and a plug drawing must be distinguished from a socket drawing. Use terminal numbers rather than an unlabelled left-to-right colour sequence.
Which pin is earth, and which pin operates electric brakes?
Pin 3 is the earth return. Pin 5 is the service-brake circuit, used for compatible electric trailer brakes through a correctly installed controller. Pin 6 operates the stop lamps and is a separate circuit.
Why do the stop lamps work while the electric brakes do not?
The stop lamps and electric brakes use separate circuits. Working Pin 6 lighting does not establish controller operation or a working Pin 5 output. Follow the controller’s diagnostic procedure and check the trailer brake system.
Can I rely on continuity alone to check the earth?
No. A connection can pass an unloaded continuity test but perform poorly under working current. Inspect the return connections and measure voltage drop with the lamps operating. Resistance tests must be performed on isolated circuits.
Can Pin 5 power a caravan fridge or battery charger?
Do not repurpose Pin 5 for auxiliary power. VSB1 recommends reserving it for service brakes. Have the auxiliary cable, connector, protection and return path selected for the appliance or charger’s load.
Does every Australian GWM Cannon have this socket fitted?
Do not assume so. Inspect the actual socket and identify the vehicle variant, build date and tow package. This guide describes an Australian 7-pin flat connection; it does not establish the factory equipment or active circuits of every Cannon.
References and related reading
- VSB1 Revision 6: Australian trailer connector assignments.
- ADR 42/05: electrical wiring and connections.
- GWM Cannon brake controller installation guide — use with the supplied controller manual.
- GWM Cannon parts and accessories.
