Troubleshooting Trailer Light Wiring Problems

For many people, trailer wiring repair is an infuriating encounter. However, the key is to ensure that the root of the problem has been diagnosed early on. It is highly recommended that you use a 12 volt stick-tester to examine the continuity of your wiring and plug which is essentially the first step in electrical repair.

While plug testers are made available for several types of trailer plugs, a stick tester is paramount if the reason for use is on a receptacle. Additionally, a stick tester is capable of testing wiring between connections, and they often come as affordable.

The first thing is to plug the trailer wiring into your tow vehicle while turning on the running lights. Ensure you walk around the trailer so you can examine for yourself if the lights are switched on. In the event that the tow vehicle blows a fuse, the first thing you should is to remove the tail light lenses of the trailer and check if certain bulbs are blown. Also, you should ensure that the bulb is fit in correctly. You should always note that the standard for a trailer tail light is the “1157” bulb. You can install this by a means of fitting it into the electric socket while twisting it in order for the contacts to lean on the tail light prongs.

The next thing you should take a look at is behind the tail lights and the each trailer marker light to ensure that the hot leads between the light housing are not crushed as a result of improper installation. If this happens, you should pull away the housing and ensure that the wires are run via the right channel so you could avoid smashing them during re-installation. In the possible event that some wires are exposed, you should replace them with another wire [insulated].

While the lights are still on, use the ignition key to operate turn signals either in the left or right directions. This time, you should walk around again to see each turn signal. If any lights are flashing, then you have a bad ground. To solve this, you have to unplug the trailer while connecting the light tester ground to the ground terminal of the tow vehicle. Switch on the running lights alongside the turn signal by putting the stick tester to the terminals. If all functions are still not working properly, ground the tester to the tailpipe and re-test. If the tester is now lighting without the plug ground, then you should ground the tow vehicle. Some vehicles come with 7 pin trailer wiring, and their wires may have to be replaced.

If certain functions of the plug are working correctly, it is very likely that the ground is working just fine and all you have to examine is the wiring as well as the fuse being connected to the plug. Also, test all the functions connected to the ‘Converter Box.’ If bot turn and brake are coming from the box and are not working out of the box, you should know that the converter box is bad. To solve this, you have to snip the wires while splicing another wire into the wiring joint.

Some vehicles come with factory tow packages, having a unique fuse block designed for towing. In this type of vehicle, if you notice that the signal is nit reaching the plug, use the owner’s manual in order to find the towing package fuse placement and extract them one after the other. Nonetheless, you should remember that tow packages are mostly located beneath the hood.

Now that the vehicle wiring has been deemed fit to operate, you should plug it again into the trailer and take a look at the lights. If the lights are still flashing on and off with turn signal and tail lights on, it means that the trailer ground is bad. Take a look at the white wire attacked to the plug and ensure it is rightly fixed to a frame that is temporarily fixed to the trailer tongue.

You may need to run a ground wire to the trailer light or to the trailer’s tilt bed. This way, the lights can make use of the tow vehicle’s ground.