Road Trains on the Barrier Highway and Kidman Way

Cobar sits where two long freight routes cross, so trucks and road trains are part of daily life here. This guide is for local truck operators and for anyone who drives the Barrier Highway or the Kidman Way. It covers the lighting and trailer electrics that keep heavy combinations safe, and what other drivers can do with their own lights and setup to share the road well.

How can we help?

Need it fixed?

Get a quote from a local Road Trains on the Barrier Highway and Kidman Way auto electrician, for anything from a flat battery to a full fit-out.

Get a quote

Buying parts?

Quality auto electrical parts from Ozautoelectrics, an established Australian supplier since 2010, dispatched through a nationwide network. For retail and trade buyers.

Shop parts

Doing it yourself?

Free step-by-step guides written for New South Wales conditions, with the parts you’ll need listed for each job.

Browse DIY guides

Auto electrician in Road Trains on the Barrier Highway and Kidman Way?

Are you an auto electrical business? List your business on this site.

List your business on this site

Two highways, one junction

The Barrier Highway runs about 1,012 km from Giles Corner in South Australia to Nyngan, passing through Broken Hill, Wilcannia and Cobar on the way. In NSW it carries route number A32. The Kidman Way, route B87, runs about 643 km from near Jerilderie in the Riverina, through Griffith and Hillston, to Cobar and on to Bourke. Both are sealed, and they cross in Cobar.

That makes the town a natural stop for freight. Livestock, mining supplies and general freight all move through the district, much of it in B-doubles and road trains. Cobar Shire Council lists a heavy vehicle inspection bay and rest area on the Barrier Highway on the western side of town, along with several rest areas along both highways.

Where road trains can go

In NSW a road train is a heavy vehicle towing two or more trailers, not counting converter dollies. Road trains may only use the approved network, and access to other roads needs a permit through the National Heavy Vehicle Regulator. Transport for NSW explains the different road train types and the relevant notices on its road trains page.

Rules and approved routes change from time to time, so operators should check the current network map and their own permit conditions rather than rely on old information. This guide sticks to the electrical side.

Trailer electrics on long, dusty runs

On a long combination, power for the lights and often for trailer braking systems has to pass through every plug and socket from the prime mover to the last trailer. Every connection adds a little resistance. On the Barrier and the Kidman, add red dust, heat and long hours of vibration, and connections wear faster than they would on city work.

Common faults on trucks working out of Cobar include:

• Dust packed into sockets that have lost their lids, leading to poor contact.
• Corroded or loose earth pins, giving dim or flickering lights at the rear.
• Pins pitted from being pulled apart under load.
• Suzie cables chafed where they rub on the deck or catwalk.
• Lights shaken loose or cracked on corrugated side roads into stations and mine sites.

Finding the voltage drop

If the back trailer's lights are dim, measure the voltage at the truck batteries and then at the rear lights with the lights on. A big difference means a poor connection somewhere in between. Work forward one plug at a time until you find where the voltage falls. Our multimeter guide shows how to take the readings.

LED lights draw less current, so they lose less voltage over a long combination, and they handle vibration better than globes. They won't fix a bad earth, though. Make sure each trailer has a proper earth path back through the plug.

24V systems and the heat

Most heavy trucks run 24V from two 12V batteries in series. In Cobar's summer heat, batteries wear faster, and a weak battery in a series pair drags the other down with it. Test each battery separately rather than only across the pair, and replace them as a matched set when one fails.

Don't take 12V for a radio or fridge by tapping across one battery. Use a 24V to 12V converter sized for the load, with its own fuse. The alternator also works hard on long runs with air conditioning and lights on, so belt tension, clean terminals and a good engine earth strap are worth checking at each service. See our guide on how to tell if an alternator needs replacing.

Daily checks before heading out

A quick electrical walk-around before each run saves a lot of trouble on roads where the next workshop may be hours away. With the lights on and someone in the cab working the brakes and indicators, walk the full length of the combination. Look for dead or dim lights, cracked lenses, plugs that are not fully seated, missing socket lids and cables hanging low enough to catch on the road or a ramp. Clear dust from plugs before connecting them, and carry spare globes, fuses and a spare plug in the cab.

For car and caravan drivers: sharing the road

If you drive the Barrier or the Kidman in a car, ute or with a caravan, your own electrics matter around trucks too. Working brake lights and indicators tell a truck driver behind you what you are doing, and they need a long way to slow a loaded road train. Check your trailer or caravan lights before every trip. Our guide why aren't my trailer lights working runs through the common faults.

At night, dip your high beam and switch off driving lights when a vehicle approaches. NSW rules require low beam when an oncoming vehicle is within 200 metres or when you are within 200 metres behind another vehicle, and the NSW Government's lights and horns page sets out the details. A UHF radio is also handy on these highways, as many truck drivers use one to talk about overtaking and road conditions.

Getting truck electrical work done in Cobar

Some truck electrical work can be done on site at a depot or station, which saves moving a long combination. Bigger jobs may need a workshop. Look for an auto electrician who works on 24V systems regularly and carries the right plugs and testers. If a part has to come in, a remote town can mean waiting, so carry spare globes, fuses and a spare plug.

For local advice, see our Cobar page. Station operators south of town can find more on our Nymagee page.

Parts for this job

Order quality parts online from Ozautoelectrics, dispatched Australia-wide.

Get it done: get a quoteDo it yourself: shop 24V LED trailer lights

Get it done: get a quoteDo it yourself: shop suzie coils

Get it done: get a quoteDo it yourself: shop 24V to 12V converters

Questions Cobar drivers ask

Why are the lights dim on my back trailer?

Usually it's voltage drop through the plugs and cables between trailers, often caused by dust, corrosion or a poor earth pin. Measure the voltage at the truck batteries and at the rear lights with the lights on, then work forward one plug at a time to find where the voltage falls. Clean or replace the bad connection.

Where can I check road train routes around Cobar?

Road trains in NSW must use the approved network shown on the National Heavy Vehicle Regulator's network map, and access to other roads needs a permit. Transport for NSW explains road train types and the relevant notices on its website. Check the current maps and your permit conditions before you plan a route, as they can change.

What should I do when a road train is behind my caravan?

Keep a steady speed, keep left and make sure your caravan's brake lights and indicators work, so the driver knows what you are doing. When it is safe, let the truck pass. A UHF radio helps, because many truck drivers use one to talk about overtaking. Check your lights before every trip.

Need an auto electrician in Cobar?

Find local auto electricians and mobile services in the Cobar directory, or start with your area: Cobar.

Run an auto electrical business in Road Trains on the Barrier Highway and Kidman Way?

• New to Ozautoelectrics? Apply for trade pricing on quality auto electrical parts.
• Already a trade customer? Log in and order parts at your trade price.
• Want more local customers? List your business on this site so drivers in Road Trains on the Barrier Highway and Kidman Way can find you.

Not confident doing this yourself?

There’s no shame in handing it over. A local auto electrician can diagnose the fault properly and get it done safely, especially for anything involving brakes, airbags, hybrid systems or air-con gas.

Get a quote from a local auto electrician Or shop the parts and do it yourself