Fixing Tail Lights Not Working: RV Tail Light Wiring Diagram

When you are going to be towing a nice, expensive trailer, one thing you will need is working tail lights. You need to get that connection put together just right or you may find that your tail lights do not work as they should and that is not good.

Sometimes it is your ground connection that is at fault. Other times it may be the connection or connector that messes up your lights. Here is a link to a couple of diagrams that should help you figure out your problem.

To learn more about RV tail lights not working just continue to read our article. It has the information you need to know about to travel safely to your next destination. Take a few minutes to see if this data will help you.

Typical RV Tail Light Wiring Diagram


That link will show you several different diagrams to help you understand the complex 7-pin connector system most RV trailers use. White is usually your ground wire and it needs to be connected to the right piece of metal, without rust, so that the whole system works correctly.

This link will take you to a Thor wiring diagram and that website has several of them as well. Unfortunately, we cannot link to all the different electrical diagrams for all RV models.

Keep in mind that the wiring in your RV and your trailer are color-coded for easier repair and connection.

What Color Wire Is Tail Lights On a Trailer?


The good thing about modern technology and RV construction is that the manufacturers color code the electrical system to make connections a lot easier. For a 7-pin connector, the tail light wire connection is red. You hook red to red to get tail lights.

This may not always work out as some 7-pin connectors or trailers may have been rewired by the previous owner or they are faulty. If you have connected the two pieces together correctly, and do not get tail lights, then you could have a short, loose connection or trouble with the wire itself.

Also, colors may change when you go to a 5 or 4-pin model of connector. Just make sure you know what you are doing before you connect the trailer’s electrical system to your tow vehicle.

Which Tail Light Wire Is Positive?


Generally, the black-colored wire is the positive one while the white wire is your ground. That is the way it is on most electrical systems. However, if you see a fuse connected to a non-black wire, that should be the positive wire. A fuse is only attached to the positive side of the system

To be sure, you should get a multimeter and test each wire and see which is the positive and which is the ground. Remember, some owners may have had trouble in the past and may have rewired things to fix their problems.

Do not assume when it comes to which is the positive wire as you could be in for quite a shock.

Travel Trailer Tail Light Wiring


The size of trailer will make a difference in how the trailer is wired. Also, the size of trailer will determine which wire goes where. Smaller 4 and 5 pin connectors use brown wires for the tail lights.

That color of wire also runs different lights on top of the tail lights. But on the 7-pin connector, you are looking for the red wire if you need to troubleshoot your tail or brake lights.

The indicator lights on a 7-pin system can be yellow for the left and green for the right with the blue operating any fog lights you have on your trailer. Or the blue wire operates the electric brakes. Each trailer may have some differences so double-check with an expert to make sure.

How Do You Wire an Aftermarket Tail Light?


Some people like to change from the traditional style of tail light to an LED style. They think it makes their trailer look better or the tail lights can be brighter and seen easier.

The first step you take is to remove the old tail lights. Then the second step would be to remove any light bulbs. make sure to label each wire you remove as tail, stop, signal light, and so on. so you do not get confused when you hook them back up again.

If your new LED system is not a plug-and-play model then you simply connect red to red, black to black, and on down the line. Once you have completed the wiring connections, make sure they are solid, and then put the LED lights into the old tail light spots.

Why Are My Camper Tail Lights Not Working?


The simple reasons for this situation would be there is a short in the system, a wire came loose, or you have a bad connection. These issues can arise at any time depending on the age of your camper or the weather conditions you camp in.

To fix those issues, you would have to trace the wires to make sure none or loose or that no corrosion has impeded the connections. Then you would need a multimeter to find the short.

Another problem would be that you put a wire in the wrong spot when connecting to the connector. This will take some time to figure out where the wire should go especially when all the other wires are working normally.

Some Final Words

When it comes to trailer lights and electricity if you do not know what you are doing or are unsure of your ability let a professional handle the connection. Many things can go wrong.

If you do not have enough training in electrical systems, you could make things worse. The diagrams linked above will help but you need to be able to understand them to fix any problem.

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