True MODS 4-Way Flat Trailer Light Tester 4-Pin Wiring Circuit Test

The True Mods 4-Way Flat Trailer Wiring Tester is not just a useful tool—it is an absolutely essential piece of equipment for any trailer owner. This compact, clever unit completely changes the way you troubleshoot trailer lighting issues, making what is usually a frustrating process quick and straightforward. The Problem Solver The biggest pain point with trailer wiring is having to constantly hook up and unhook your tow vehicle just to see if a light is working. This tester eliminates that hassle entirely. This unit allows you to diagnose your entire lighting system without ever connecting the trailer to your car or truck. All you need is a simple 12-volt battery and a couple of wires to power the tester. Once connected, you can perform comprehensive checks on: Running Lights Brake Lights Turn Signals (Flashers) Emergency Blinkers Operation and Effectiveness The design is simple and highly effective. By providing power directly to the trailer plug through the tester, you can isolate and test each circuit individually. I was personally able to diagnose and repair my trailer lights quickly thanks to this invaluable tool. Instead of playing the frustrating "guess-and-check" game with the vehicle, I could pinpoint exactly which wire or connection was faulty on the trailer itself. This not only saved me considerable time but also prevented wear and tear on my vehicle's electrical system. Final Verdict If you own a trailer of any kind, the True Mods 4-Way Flat Trailer Wiring Tester is a must-have addition to your toolbox. It is a small investment that pays massive dividends in time and frustration saved. Its ability to turn a complicated diagnostic task into a simple bench test is brilliant. Rating: 5 out of 5 Stars. This tool is a true game-changer for trailer maintenance.

This simple device is great for testing out the wiring on any vehicle that has a four prong trailer plug. It is well-made. It is compact which makes it easy to store. The four indicator lights on it, enable you to determine if one or more than one of the prongs are not working properly.

Great tester for your towing harness. Takes the headache out of seeing if your harness is connected correctly and working.

I like this item so easy to use. But it really only tells you if your getting power to the back of car. Lights on trailer are out but I know I have power as far as the back of the car. Kinda handy !

Excellent and inexpensive 4-pin trailer light tester. Highly recommended!

Simple and easy trailer light / wiring tester, great price and fast shipping.

This 4-Way Flat Trailer Wiring Tester was exactly what I needed to troubleshoot a wiring issue on my Dodge truck. The LED lights are bright and clearly labeled, making it really easy to see which functions (turn signals, brake lights, etc.) were working properly. It plugged right into the trailer connector with no hassle and helped me diagnose the problem in just a few minutes. Solid little tool—simple, effective, and a real time-saver. Definitely a must-have if you tow or work on trailer wiring regularly.

As a "Do it Your Self" or a Pro Auto Tech, this is the kind of stuff you should always have in stock at your tool box or garage, you will remember me when you will need it... have it or not...

The fact that it works if a trailer is plugged in or not

Très efficace pour trouver un problème de connection. En moins d’une minute tout était réglé.

Worked as described

I tried this item and none the lights lit up. I checked and followed the instructions and nothing lit up.

When I plug it in to the truck and trailer the lights are upside down so it's kind of hard to see but still works.