HomeServicesTowbar & Trailer Wiring / Brake Controllers
A new towbar with no socket, trailer lights that flicker, a caravan with electric brakes and no controller: these are the jobs that bring towing vehicles into our workshop. We handle the auto electrics in Logan side of towing, from the plug at the back to the controller at the wheel.
Our trailer wiring in Logan and towbar wiring cover flat and round 7-pin and 12-pin sockets. We also fit Anderson plugs so the caravan battery charges on the road, along with brake controller installation and breakaway wiring. You book the vehicle in and leave it with us at our Logan-based workshop, close to Slacks Creek and Springwood.
The work follows Queensland towing rules from the Department of Transport and Main Roads, including the QLD-wide requirement that trailer brakes be operable from the driver's seat. We test each circuit with the trailer connected, so a fault shows up in our bay and not on the highway. Call 07 3566 2108 or use the quote form on this page to book the vehicle in.
Most towing setups come down to four jobs: the right socket, a brake controller, a heavy feed for the caravan battery, and a breakaway system. Here is how each one works.
Light box trailers and older caravans mostly use a 7-pin plug, in flat or round form. Larger caravans and some camper trailers use a 12-pin plug that adds a reversing feed and a charge line. We fit the socket that matches your trailer, or an adaptor if the plugs differ. Many newer vehicles use CAN-bus lighting systems, and those need an interface module so the trailer lights don't upset the car's computer.
An electric brake controller turns your pedal pressure into a signal for the trailer's brakes. Timed controllers apply a set output, while proportional controllers follow how hard the vehicle is slowing. We mount the unit within the driver's reach, wire it to the brake circuit and set the gain for the trailer you tow. REDARC is one example of the gear we fit, and we are not a dealer for it. A controller set too high can lock the trailer wheels, so setup matters as much as the unit.
Caravan and camper batteries only charge on the road if the cable feeding them is heavy enough for the distance. Anderson plug installation starts with a correctly sized cable from the vehicle's battery to the rear, with a fuse at the source. The cable ends in an Anderson plug, and it often feeds a DC-DC charger on the trailer so the battery is charged properly rather than starved. Without a heavy feed, a fridge and lights can run a caravan battery flat in a short stay.
A breakaway system applies the trailer's brakes if the trailer ever detaches from the vehicle. Under the Queensland rule it must keep them applied for at least 15 minutes. We fit the breakaway battery and pull-pin switch, wire them into the brake circuit and test that the brakes lock on when the pin is pulled. The breakaway battery has to stay charged to do its job, so it is worth checking it before each trip. It is a small part that matters a lot if a coupling ever fails.
Every towing job runs through the same four steps, whether it is a simple socket or a full controller and charging setup. Nothing gets skipped because the job looks small.
We check which plug the trailer carries, what wiring the vehicle already has and the condition of the towbar. Towbars made after 1 January 1992 for passenger vehicles should be marked with their load capacity and the make and model they suit.
New cable is the correct gauge for the load and fused near the battery. It runs clear of exhaust heat, moving suspension parts and sharp edges, held in loom and clipped so it can't chafe through. Every circuit gets its own fuse protection where the load calls for it.
The controller goes where the driver can reach it without taking their eyes off the road. We set the gain using the trailer's load where possible, because an empty trailer and a loaded one brake very differently. We then explain what the controller is doing so the setting makes sense.
With the trailer connected, we check the lights, the brake output and the charge feed. Queensland guidance tells drivers to check that brake and light connections are secure and all lights work. We do that before the vehicle leaves, and it is a good habit to repeat before every trip.
Book the vehicle in and we'll test it and price the repair before any work starts.
Tow along the Mount Lindesay Highway or take the M1 south to the Gold Coast, and the same Queensland rules apply. These are QLD-wide Department of Transport and Main Roads (TMR) rules, summarised here in plain words.
A single-axle trailer up to 750 kg Gross Trailer Mass (GTM) needs no brakes. Other trailers up to 4,500 kg ATM need an efficient brake system that complies with ADR 38. Except for over-run brakes, trailer brakes must be operable from the driver's seat. Over-run brakes are only allowed up to 2 tonnes GTM, and every trailer over 2,000 kg GTM needs brakes on all wheels.
The breakaway rule applies as well. The towing vehicle also needs sockets for trailer lighting, and may need suitable brake connections. Under Queensland Government rules, towbars and couplings must not cover the number plate or rear lights when no trailer is connected.
We wire to these rules and test the result. We don't certify compliance, so check your own trailer's weights and requirements with TMR.
Here is what happens to your vehicle at our workshop, from the first plug to the final check.
Before handover we connect the trailer and test each circuit: indicators, brake lights, tail lights, the brake output and the charge feed. If something doesn't respond the way it should, we trace it and fix it rather than hand the vehicle back with a note. You get a trailer that works as a complete system, not just a plug that looks right.
We set the controller's gain for the trailer you tow and show you how to adjust it. A caravan loaded for a long trip needs a different setting from the same caravan empty, so you leave knowing how to change it yourself, and why it matters on a steep or wet road.
Connectors under the vehicle are sealed against Queensland rain and road spray, and the cable is covered where it passes near heat or moving parts. A tidy run is easier to inspect later and far less likely to fail on a trip. Moisture in a join is a common cause of flickering trailer lights, so we seal them.
The price of a brake controller installation depends on the controller, the vehicle and how far the cable has to travel. The same applies to sockets and Anderson plugs. We quote after seeing what your vehicle needs, so use the form beside this page and we'll give you a free written quote.
Timed and proportional controllers cost different amounts to fit. Dash-mounted units go in differently from remote ones, and the mounting spot changes the wiring time.
Some vehicles have a pre-wired harness behind the bumper or dash. Others need a full cable run, and CAN-bus vehicles may need an interface module as well.
A heavy cable from the front battery to the rear takes time and material. A longer vehicle or a hard route to the back means more of both.
A breakaway kit adds parts and wiring. Extra sockets, such as a second plug for a different trailer, add to the job too.
No. Queensland rules say that, except for over-run brakes, trailer brakes must be operable from the driver's seat, and the controller is what makes that possible. Without one, the trailer's brakes simply won't work when you press the pedal.
Yes, you still need a brake controller if your trailer has electric brakes, even with a 7-pin trailer plug fitted. The plug carries the signal and power connections, but the controller is what drives the electric brakes. A socket on its own doesn't brake the trailer.
Some people do install an electric brake controller themselves, but wiring gauge, mounting position and setup all matter. A workshop fit includes a correctly sized and fused cable, a secure mounting spot, the gain set for your trailer and a test with the trailer connected. In Queensland, brakes must be operable from the driver's seat, so the mounting spot matters.
A correctly wired brake controller draws next to nothing from the battery when it is off. Problems usually come from wiring faults, such as a feed taken from the wrong circuit or a poor connection that leaves something live. If your battery goes flat after a controller is fitted, we trace the draw.
The Australian standard for 7-pin trailer plugs assigns each pin a function and a wire colour. Older trailers and imported plugs often don't follow it, so colours alone can mislead. We test each circuit on the trailer rather than trust the colours.
Your caravan battery usually isn't charging while towing because of thin cable, a missing DC-DC charger, a blown fuse or a poor Anderson connection. Long cable runs lose voltage, and a loose or corroded plug adds to the loss. We test the feed at both ends to find the weak point.
In Queensland, a single-axle trailer up to 750 kg GTM needs no brakes, while other trailers up to 4,500 kg ATM need brakes that comply with ADR 38. Over-run brakes are only allowed up to 2 tonnes GTM, and every trailer over 2,000 kg GTM needs brakes on all wheels. These are TMR rules that apply across the state.
Call 07 3566 2108 or send the form to book your trailer wiring or brake controller. Tell us what you tow, and we'll tell you what it needs.