Electric Trailer Brakes Not Working : Causes & How To Fix

Trailer Brakes Not Working

Trailer brakes not working can be a really serious problem when you ignore this problem and drive your towing trailer at high speed. Because trailer brakes do not work properly, the trailer may push your towing vehicle while stopping at high speed, causing the towing vehicle and trailer to lose control. Therefore, whenever you are going to tow a small or big trailer, definitely check its brakes before pulling the trailer. However, there are many reasons why a trailer brake may not work.

In this post, you will go through the reasons behind trailer brakes not working in detail so that you can investigate the problem and take possible steps to fix it.

Why Your Trailer Brakes Not Working – Causes

If your trailer brakes are not working, common causes are corroded or loose electrical connections, worn brake pads, wiring problems, blown fuse, faulty brake control, worn magnets, improper adjustment, or incorrect brake light signals.

Let us know in detail why trailer brakes do not work, so that you can investigate this problem and take appropriate steps to fix it.

1. Loose Power Connections

Most trailers have electric brakes. So if your trailer’s brakes are not working, the first thing you should do is check the electrical connections between the tow vehicle and the trailer and make sure that the electrical connections between the towing vehicle and the trailer are not loose.

Because loose or rusted connections can cause trailer brakes to fail, Also, make sure that your trailer is securely attached to the towing vehicle. Any trailer brake wiring system gets worn out after prolonged use, and if you are driving the trailer on rough roads, these connections can become loose due to shaking.

2. Blown Fuse

As you may know, a fuse box is installed to protect the electrical operation of the towing vehicle and trailer and to protect against any other short circuit. Where the fuses related to the tow brake system and other functions are located. But sometimes the fuse related to the electrical supply between the towing vehicle and the trailer blows and the trailer brakes may become unable to function.

Because a blown fuse does not supply power. So when your trailer brakes are not working, don’t forget to check the trailer brake system fuse.

3. Faulty Brake Controller

In many cases, a faulty brake controller can also cause trailer brakes to fail to function. Because the faulty brake controller becomes unable to send electrical output signals to the trailer brake unit,

Many times, drivers forget to set the brake controller to the correct setting as per the weight and braking requirements of the trailer. Because the incorrect setting of the brake controller may impair the functioning of the trailer brakes,.

4. Worn Brake Pads

If a trailer’s brake pads are excessively worn, this can also be a cause of the brakes not working. Because worn brake pads do not properly press against the brake drum or rotor, the brake pads lose friction or grip, and the worn brake pads are unable to slow or completely stop a spinning trailer wheel.

5. Brake Fluid Issues

If your trailer has hydraulic brakes, check the brake fluid level in the master cylinder. Sometimes the brake master cylinder gets damaged or leaks, due to which the brake fluid starts leaking and the brake fluid level reduces.

Therefore, when the brakes are applied, proper hydraulic pressure is not created in the hydraulic brake system, due to which the trailer brakes do not work. Additionally, brake fluid leakage in the hydraulic brake system can also cause this problem.

6. Defective or Worn Magnets

If you press the brake pedal on the towing vehicle and all electrical connections to the trailer’s brake system are properly connected, But if you still don’t see any response in the trailer brakes, the magnets in your trailer’s brake system are probably faulty.

Because when an electric signal is sent from the towing vehicle’s control unit to the trailer brake unit, the magnets in the trailer’s brake system are activated, which pushes the brake pads toward the drum, causing friction between the brake pads and the drum. Is. But when there are faulty magnets in the trailer brake system, these can also cause the brakes to not work.

7. Corroded Grounding Connection

Many times, due to prolonged use, the grounding connections of the trailer become damaged due to water or weather effects. If your trailer’s grounding connection is faulty or damaged, your trailer’s brakes may also not function properly.

A faulty grounding connection will also not properly transmit the electrical signal from the towing vehicle’s brake controller to the trailer’s brake system, causing the trailer brake magnets not to activate. Therefore, trailer brakes may also not function due to a poor grounding connection.

How To Fix Trailer Brakes Not Working?

To fix trailer brakes that are not working, you first need to identify the underlying issues and then take some possible steps to resolve them.

1. Do A General Checkup

First, you should inspect that your trailer is securely attached to the tow vehicle. To check this, depress the brake pedal on the towing vehicle before pulling the trailer and also try sliding the trailer back and forth.

2. Inspect The Wiring & Connections

Your next step should be to check the wiring and fuses connecting the trailer brakes to the brake control. During inspection, check that all connections are secure and free from rust. Because a damaged connection or blown fuse can shut down your trailer’s brake system. So if you find any damage to the wiring connections or fuses during inspection, replace them with new ones.

3. Check Brake Fluid Level

If your trailer has a hydraulic brake system, check the brake fluid level in the trailer’s master cylinder. Because low brake fluid levels disrupt the functioning of your trailer’s hydraulic brake system. So if the brake fluid level is low, top it up. Also, if you notice a fluid leak around the brake lines or brake components, get the leak properly repaired.

4. Check The Electric Brake Magnets

Keep in mind that most trailers use electric brake systems. In which an electronic signal magnet plays an important role. If your trailer also has electric brakes, inspect the brake magnets for any failure or damage. To test this, measure the resistance of the magnets using a multimeter. If its measurement shows a high reading, it indicates a bad brake magnet. If this happens, replace the brake magnet with a new one.

5. Check Brake Control Settings

Whenever you connect the trailer to the towing vehicle, properly adjust the settings on the tail brake control and make sure it is set correctly for your trailer’s braking system. Because incorrect setting of the brake controller can also interfere with the functioning of the trailer brakes.

6. Test The Brake Signal

Check the brake signal with a circuit tester or multimeter to make sure the brake signal is reaching the trailer brakes when the brake pedal is pressed. If no signal is being received, there may be a problem with the brake switch or wiring between the brake pedal and the trailer brake. To fix this, replace the bad wiring or bad brake switch.

7. Inspect Brake Components

If your trailer’s brakes still don’t work after doing all this, inspect the brake components themselves. Inspect for damaged brake shoes, springs, or other components in the trailer’s brake unit, and make sure the brakes are not excessively worn. If you notice any damage to these components, replace the defective component or perform appropriate repair.

​Trailer Brakes Not Working But Lights Are

If your trailer’s brakes are not working but the tail lights are working, it could also be due to an incorrect setting of the brake controller. So the first thing you should do is check the brake controller settings. You will then need to check the brake wiring for any loose connections and also check for wear or damage to the brake magnets.

If the problem persists after checking all these, check the ground connection at the trailer brake. Because a poor ground connection to the trailer can impair the functionality of the brake system. Also, check the brake fluid level. If the fluid level is low, top it up. After doing all these checking processes it will definitely help you in solving this problem. However, this can be time-consuming and a matter of experience.

How To Test Trailer Brake Magnets With A Multimeter?

First you need to disconnect the power wiring from the brake magnet. Then, using a multimeter set to measure resistance, attach a probe to each terminal of the magnet. A properly functioning brake magnet should display a reading between 3 and 5 ohms when tested.

If the resistance of the brake magnet appears abnormal, it is a symptom of a short circuit or open circuit in the magnet. Additionally, inspect the brake magneto for other damage or wear.

Because this type of damage also affects its performance. So if the resistance reading shows abnormal during multimeter testing, replacing the brake magnet is a better option for safe and effective braking performance.

Why Are Electric Trailer Brakes Not Releasing?

If your trailer’s electric brakes are not releasing, there are several possible causes that will need to be investigated and then worked on to fix.

  • First, check the proper adjustment of your trailer’s brake control. If it is not properly adjusted, adjust it properly.
  • Next, if you find any loose or rusted electrical connections, clean and tighten them and replace them with new ones if the wires are damaged.
  • Next, you should check the brake magnets. Use a multimeter to test its functioning. If the brake magnets fail the test, they replace the brake magnets with new ones.
  • If your trailer brakes still won’t release, the problem could also be caused by a faulty brake controller, which will need to be replaced. Because a bad brake controller may be unable to send an electric signal.
  • You should pay attention to regular maintenance of your trailer’s brake system components. Because lack of regular maintenance can also prevent the brakes from releasing.


Q. Why are trailer brakes not applying when I press the brake pedal?

Possible causes of this problem may include a faulty brake controller, disconnected wiring, or faulty brake magnets. To resolve this issue you should check these components. Should be repaired or replaced if necessary

Q. What to do if trailer brakes feel weak or sluggish?

Typically, weak or unresponsive trailer brakes are caused by low brake fluid, worn brake pads, or air in the brake lines. To troubleshoot this you will need to inspect the trailer brake fluid level and check for brake pad wear, and bleed air from the brake lines if necessary.

Q. Why do trailer brakes lock up excessively when braking?

If the brakes lock when you apply the brakes on your trailer, common causes are an out of adjustment brake controller, contaminated brake linings, or a faulty brake actuator. Therefore, attention should be paid to its regular maintenance for better trailer brake performance.

Share If You Like

Leave a Comment

error: Content is protected !!