Wiring your teardrop trailer for navigational wiring can be tricky, so for those of you that might feel uncomfortable doing this aspect of the build, I would recommend having a professional do that for you. Sure, this will add an additional cost, but for some people this added cost could save them money in the long run, and certainly your time as a professional could probably wire the navigational lights on your teardrop trailer in an hour or less.

Now, you may be curious as to why I didn’t recommend doing this step when you were flooring your teardrop in the beginning of this build, but the answer to that question is very simple and it involves problems with this wiring as time, age and wear take a toll on them in the future. Simply put, it’s not uncommon for wiring connections to loosen, become corroded or even worn when the wires rub against steel framework as you travel down the road.

For those reasons, wiring your navigational lights through the flooring framework of your teardrop would not be a good decision. Should one (or more) of your lights fail for problems other than the obvious burned out light bulb; what are you going to do to find the issue?

Are you going to start destroying the flooring in your camper to make sure your driver’s side amber marker light is working? Do you want to do the same thing in your hatch area trying to determine why your license plate light isn’t working? Obviously not, so your best option is to wire these components on the underside of your teardrop’s flooring plan and in most cases through its steel framework crossbars to keep the wiring from ever getting loose from connectors that would keep the wiring in place.

This task can be more easily installed prior to building the house area on your frame, but it can also be installed later in your build. Personally, I would install this part of the wiring early in the build and test its wiring periodically throughout the build.

Let’s start with a wiring harness.

Diagram 1. (Photo credit Michigan Truck Spring)

One set of five pin connectors for your RV and the tow vehicle will be needed to install your navigational wiring. This will allow you to wire all required lighting allowing you need to drive legally down the road and it will give you an extra wire to supply a source to re-charge your RV’s onboard power battery supply as well.

Photo credit: Amazon.com

I recommend purchasing a 5-pin wiring harness that has plenty of wire such as the one shown here. This particular harness has leads that are 25’ feet in length. While this may seem excessive, keep in mind that your wiring may not go directly to where it is needed. Instead, you may need to wire it alongside of your frame so you will need so extra wire.

Pro tip: Always keep in mind that it is better to have too much wire than too little wire.

While this harness may seem long, it’s relatively inexpensive and easy to cut to the proper length. On the other hand, buying a shorter length harness and coming up short of needed wire, causes more problems than what the monetary savings are worth. And remember, any unused lengths of wire can be coiled up and saved for future use when you made need a piece of wire in an emergency.

The lights

Photo credit: HomeDepot.com

I also recommend purchasing a kit of lights just to keep the installation process simpler. The cost of this lighting kit is under $30 and while the wiring harness is too short for your build, you can easily use this light kit for your wiring with the longer harness listed above. And again, if you don’t use the harness supplied in this kit, you can always stow it away for future uses, or you may someday be the person that saved the day for a fellow RVer that’s stranded on the road for lack of a few wires or an electrical connector.

Of course, you can always buy other types of lights from other sources that may more work more aesthetically with your design and that chose is yours as well. As a rule, the wiring will always be the same, so the choices are almost endless when it comes down to finding the lights that work best for your rig and still fall within the requirements of the national motor vehicle codes.

Protecting your wiring

Photo credit: Harbor Freight

Another important key to wiring your navigational lights on your teardrop build is to properly protect your vital wiring needed to travel. Corrosives such as magnesium chloride and salt used for de-icing roads will corrode your wiring and electrical connections. In fact, in some states such as Colorado, it’s not unusual to find traffic signals or roadway signs out-of-order because the chemicals they routinely spread on the roads during inclement weather corrode the protective coverings on the wiring needed to run those traffic control devices properly.

It’s important to use a plastic casing to enclose your wiring when it’s exposed to the elements. Additionally, if you are installing your wiring through any trailer framework, this protective casing will prevent the wiring from rubbing against the bare metal which could cause the plastic coating on the wires to wear thin or off. When this happens, the wiring will develop small areas of worn coating which will expose bare wire and when that comes in contact with your metal framework it will ground that circuit and whatever lights are wired through that particular electric line will stop working or they will flicker on and off as you travel down the road.

This protective covering is inexpensive and well worth the cost. A ¼ inch by 14’ feet section of this casing sells for less than four dollars and is absolutely necessary when installing your navigational wiring. Unless you purchase a roll of this product, it’s likely that you’ll be purchasing it in smaller lengths. While it’s crucial to not have any splices in your wiring, it’s fine if you join the protective casing together in some spots using electrical tape or any other type of tape suitable for the elements you’re living in or traveling through.

Wiring the navigational lights

Diagram 2. (Photo credit Michigan Truck Spring)

While this diagram represents a four-wire pin connection, the same theory can be applied to a five-way wiring schematic. The extra (blue) electric line will be used to supply voltage to your RV’s onboard battery that supplies power to your 12v lights and other outlets while you are camping.

In this diagram, you’ll see that the brown wire is supplying electric to the right rear taillight and then into a series of marker lights located along the rear framework of the trailer. Since your teardrop camper will be less than 80” inches wide, you won’t need those additional marker lights, but you should still wire in a light that illuminates your trailer’s license plate using that circuitry.

Also, please note that with the five-pin wiring harness shown above, the blue auxiliary wire and the white ground wire are not the same length as all the others. The white ground wire is simply attached to your trailer frame using a screw or small bolt which can be done much closer to the pin connector, so it doesn’t need to be the same length. Additionally, the blue auxiliary wire used to keep your house battery charged by means of your tow vehicle and that’s shorter as well. This is because most RVs are designed to have their house batteries toward the forward area of the camper so that line is usually shorter. In the second part of this wiring your teardrop camper tutorial, I’ll explain how to install the living area part of your wiring and where you should locate your batteries as well as the components needed for that system to operate on shore power and through your tow vehicle’s electrical system.

What about the wiring connector on the tow vehicle?

To be honest, I would not recommend doing this step yourself. There are too many variables in the wiring systems of new model vehicles, and it would be best to take your tow vehicle to a trained professional to have this step done. Generally, you can have this done at any RV repair center, but I have always taken my tow vehicles to a U-Haul rental center found in most metropolitan areas in the country. They are reasonably priced, and they also specialize in the installation of tow hitches so you can have both components installed at the same time if need be.

As always folks, thanks for following along and be sure to check out the next article in this series where I’ll guide you through process of wiring the inside of your teardrop for 12-volt circuitry and 110v when you are using shore power.

Stay safe and I hope to see out on the road someday.

Start reading step 11: Wiring your living space