In this blog post, we will answer the question: “Why is my trailer running lights not working?” We will describe the reasons for the trailer running lights not working. We will also list a few steps to fix the trailer running lights. At the end of this post, you will get to know the common reason for the trailer running lights not working.
Why is my trailer running lights not working?
Your trailer running lights might not be working for the following reasons.
- Damaged wires
- Faulty circuit
- Corroded sockets and plugs
- Truck connector issues
- Damaged pinpoints
- Faulty ground connection
- Wrong light bulb
- Blown fuses
- Faulty control switch
- Damaged wires are the most common issue for trailer running lights not working. In most situations, the wires can be damaged and it can prevent the flow of power which can result in the trailer running lights not working.
- The circuit is the next common issue that can be the reason behind the running lights not working. The circuit can be faulty and it might need to be repaired or replaced. Checking the circuit is one way to understand where the issue persists.
Corroded sockets and plugs
- Over some time, the sockets and plugs can get corroded due to water or wear and tear. All sockets and plugs need to be replaced once in a couple of years to avoid such issues.
- Be sure to check for corroded sockets and plugs since this might be another reason for the running lights not working.
Truck connector issues
- The truck connector might not be functioning properly, thus preventing the power from passing to the trailer. It is also good to test the truck connector to know if the problem is on the trailer or the truck itself. If the truck connector is functioning properly, then the issues are on the trailer side.
Damaged or pinch points
- Damaged or pinch points are also another common issue that can be the making cause of the trailer running lights not working. Look around for damage or pinch points. Be sure that the pinch points are corrosion free.
Faulty ground connection
- A faulty ground connection can also be a reason. Hence, it is essential to check the ground connection on the trailer side as well to avoid any confusion.
Broken light bulb
- This might not be the case at all times, but brake lights have dual filament bulbs and a broken filament can be another issue.
- Manufacturers use different tail bulbs and running lights. You might need to replace the bulb whenever required.
- Blown fuses need to be checked and replaced. Incorrect amp usage can blow up the fuse and this can prevent the trailer running lights from functioning properly.
Faulty control switch
- In rare situations, a faulty control switch in the truck can also be an issue. Faulty control switches are known to be a cause but you will get to know immediately since the other lights might not function as well.
Those were some of the common issues for the trailer running light not working. If you find your trailer running light not working, be sure to get it checked with an expert. The trailer running lights are important and it is not recommended to drive a trailer around without the running lights. It is not safe and it is against the law in most states.
Steps to fix the trailer running lights not working
There is no need to panic if you find your trailer running lights not working. There are a few steps to troubleshoot and fix the trailer running lights. These steps will help you to get back on track soon. However, you will need a few tools to get started and fix the trailer running lights.
Troubleshoot the lights with a tester
- The first and most important thing is to troubleshoot the trailer’s running lights with the help of a tester.
- Ensure that the vehicle tester is inserted properly in the trailer. The plug configuration of the vehicle needs to be checked as well.
- Check the harness and examine all the possible causes. You will need to identify the cause before getting to work.
Inspect the ground wiring of the trailer
- The ground wiring of the trailer is pretty important and be sure to inspect the connections and get them cleaned. The wire must be secure and tightened to the vehicle.
- Look for rusty screws and other damage that can be present in the wiring system. Most of the trailer light issues are related to the ground wire.
- The ground wiring is the most important part and it must be maintained at all times.
Clean the connector plugs
- The connector plugs need to be cleaned and it is always advised to use a special cleaner. Do this if the trailer running lights are not working.
- You can use electric contact while cleaning the connector plugs. Be sure to get it cleaned with a wire brush and ensure not to cause damage while cleaning.
Replace the bulbs
- One of the other major and common issues is bad light bulbs. If you find the trailer light malfunctioning, be sure to give the bulbs a check.
- Removing bulbs and replacing them is easy. All you need to do is unscrew the bulbs and get new ones fixed. In some cases, it might just be one bad bulb and there is no need to change the entire set of bulbs.
Clean corroded sockets
- Corroded sockets are more common than we know and there can be several issues due to this reason. Use sandpaper to clean any corroded sockets.
- You might need to use a dowel pin that is tiny enough to enter small spaces. The contact point and the socket can be corroded in tiny places but they might stop the lights from working.
- Use 220 grit sandpaper and use the dowel pin to get it cleaned. Contact points can be cleaned by moving the dowel from side to side.
- This is one of the major reasons for the trailer running light not working. It is recommended to check the sockets every couple of years to ensure there is no problem.
Conduct a continuity test
- The wiring is the most important aspect and a continuity test will be the best option to see if the wiring is functioning properly.
- A continuity test is done by joining connector pins and jumper wires. Connect a continuity tester to the sockets to get a continuity test done.
- A broken wire is one of the most common problems that are faced. You should attach the jumper cables to the connector pins with the help of an alligator clip that is secured to the continuity tester.
- Be sure to get help from an expert if you are unable to get these problems solved on your own.
Replace the trailer light system
- If you are unable to get the issues sorted out with all the above-mentioned steps, you must consider replacing the trailer light system.
- Replacing the entire trailer light system will be the last resort and this might help you get the trailer running lights back on track.
- Change the entire wiring of the trailer in case of any damage. It is always better to replace the entire wire rather than fixing only the broken piece.
- You can also purchase a cable harness at a decent price and get it fixed over the wire for safety. In some situations, the cable harness might be the only issue that is preventing the trailer running lights from working.
- Be sure to consult an experienced expert in replacing the trailer running lights. Avoid working on your own if you are not used to working with these systems.
In this blog post, we have answered the question: “Why is my trailer running lights not working?” We have described the reasons for the trailer running lights not working. We have also listed a few steps to fix the trailer running lights. Leave us a comment below and let us know if you have a few tips to fix the trailer running lights not working.