Trailer Brakes Not Working But Lights Are – 3 Fixes

trailer brakes not working but lights are
trailer brakes not working but lights are

Road and camping trips are best enjoyed if you have a recreational vehicle. It has basic amenities, such as a bathroom, a kitchen, and a bedroom, and it also serves as your quarters.

This means you don’t have to put up a tent or other temporary structures that don’t protect well against the elements and wildlife. RVs are large and heavy vehicles. You need decent experience driving an SUV, truck, or bus to safely and efficiently drive an RV.

You don’t necessarily need to get a separate license to be allowed to drive one of these beasts like truckers, except if your RV is 40 feet long and weighs more than 26,000 lbs. But if a license is all it takes to make the most of your trip, then so be it. You should even take an RV safety course to keep away from trouble.

The dangers of trailer brake malfunction

The dangers of trailer brake malfunction

One of the things you can learn from an RV safety course is operating a travel trailer. Unlike a camper van, motorhome, or coach, a travel trailer doesn’t have an engine. Instead, it is towed by an SUV or truck. In short, the trailer is only linked to the tow vehicle via a special coupling.

As a result, you cannot completely control it from the tow vehicle. Modern travel trailers have wired amenities so they can be controlled from the tow vehicle.

The brakes, for example, are linked to a brake controller on the tow vehicle’s dashboard, allowing you to safely bring both the tow vehicle and the travel trailer to a complete stop, even abruptly. Older models lacked this feature and were unsafe to perform a hard brake.

The question is, what if the brakes fail when you do a hard brake? You probably already know what might happen, but let’s break it down for those who aren’t aware or downplay the dangers it entails.

car pedals

When you’re riding a bus, and suddenly the driver hits the brake to avoid a crossing deer or another vehicle, you’ll feel your body being pushed forward. If you’re expecting the principles of spatial relativity to apply in this situation, think again.

Only objects with negligible weight can glide safely with the things they have a gravitational relation to, like the relationship between the Earth and the Sun. The same happens to a travel trailer with faulty brakes when the tow vehicle suddenly stops.

It will be pushed forward, and depending on the speed by which the two vehicles are moving, it can crash into the tow vehicle and probably other cars in front. So, learning how to diagnose and troubleshoot faulty trailer brakes is crucial.

How do trailer brakes work?

How do trailer brakes work

Trailer brakes are electrical. Wires from the tow vehicle to the travel trailer convey electric current to activate the brakes. This current energizes the magnets in the axles, causing them to grab onto the interior of the brake drums, where the brake assembly is located.

The actuating arm then swings to the other side, pressing the brakes out. This is easier to understand if you know what’s inside a brake drum. But at the very least, it reveals the weak point of a trailer’s electrical brake system: the wiring.

The wires used in this system are not made of Kevlar or titanium. Instead, they are plain and flimsy cables with thin insulation. As a result, these wires don’t require much force to snap.

Trailer brakes not working but lights are (troubleshooting)

The brake lights are among the safety features you can rely on when driving any vehicle. But they are not always reliable. Sometimes, they come on just fine even though you are getting an error code on your travel trailer brake controller.

So which one do you trust? If you trust the brake lights, you’re not dealing with the risk of the issue being real, so it’s best to check the brakes just to be sure it’s safe to drive.

Connector Trailer

If you decide to diagnose and troubleshoot the problem, follow a systematic elimination process. Because the problem could be coming from any of the brakes and axles, this process might take long.

  • Connector – The first thing you should check is the main connector, particularly the trailer pin, linking your travel trailer to the tow vehicle. Make sure it’s not dented, worn out, or smashed. Sometimes, it gets disconnected from the tow vehicle, falls to the ground, and gets dragged as you travel.
  • Magnet sound – Remember that your trailer brakes are electrical and magnetic, so you’ll hear a hissing noise when the brakes are working. If they aren’t, you won’t hear anything. So, the next step is to check if the brakes are making that hissing noise. If not, proceed to the next step.
  • Broken wire – About 90 percent of all trailer brake failure cases are due to faulty wiring. In fact, you can immediately assume that one of the wires is broken without going through the process of elimination and be right 90 percent of the time. But following the process yields a better result, so you better stick to it.

The electrical wires snapping or getting damaged has to do with poor installation and the connectors used. Most wires in RVs are installed as they are—no ethylene tetrafluoroethylene (ETFE) tubing for added protection. Not even ties to secure them in place. Also, most of these wires are connected by scotch locks.

Why scotch locks must be banned

Why scotch locks must be banned

A scotch lock is a type of connector that clips a wire with a tiny spade. While it is a standard locking mechanism, it damages the wire. The spade is designed to puncture the wire’s insulation and serve as an anchor.

With a hole in the insulation, the copper wire inside becomes exposed to the elements, leading to corrosion and, eventually, an electrical connection failure. Most RV owners don’t mind this, but from a technician’s point of view, this should be changed.

Some even suggest banning scotch locks from being used on any wiring. If a product compromises the integrity of your RV’s electrical circuit, it has no place in any assembly, let alone in something as critical as a brake system.

Why connect wires with heat-shrink butt connectors

connectors Trailer

A better alternative to scotch locks is heat-shrink butt connectors. Also called heat shrink splice connectors, they come pre-insulated. To use them on your trailer brake system, strip the wires, insert them into the connectors, and shrink the tubing with a lighter or safe heat source.

The process may not be as easy as connecting wires with scotch locks, but it’s easy enough for those with limited electrical experience to perform.

Two ways to diagnose and troubleshoot your trailer brake malfunction

Troubleshoot your Trailer Brake

Once you confirm that there are no damaged wires outside the brake drums, it’s time to check the wiring inside the brake drums. Unfortunately, these drums aren’t very easy to access. You’ll have to take apart a portion of the wheel and axle to open the drum and access the wires.

There are two things you can do at this point. Either you go so far as to open the drum and perform a voltage and current test (to determine if electricity is passing through those wires) or leave the drums intact but cut the cables that go into the magnets or axle tubes. You may wonder why on Earth you would cut the wires.

This isn’t standard advice, but something you can do if you plan to replace the scotch locks with heat shrink butt connectors. Since you’ll have to cut the wires during the replacement, you might as well take advantage of the process to see which brakes are getting power and which are not.

Conclusion

Conclusion Trailer Brake

Some of the work involved in repairing and maintaining your RV requires technical skills. While you won’t learn everything, it’s in your best interest to know at least tasks like troubleshooting trailer brake problems.

Not only will that save you money on professional repair, but it will also save your lives. Besides, professional help won’t always be available.

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