4 Pin Trailer Tester: This trailer plug tester quickly verifies the operational status of vehicle trailer wiring harnesses, pinpoints issues within lighting systems, and doubles as a standard 4-pin male/female connector.
Plug-and-Play Design: Simple and Convenient Operation - Simply plug the trailer wire tester into the 4-pin flat trailer connector on the tow vehicle to instantly test whether the tail lights and turn signals are functioning properly, with no setup required.
High-Brightness LED Indicators: Every trailer connector tester is equipped with high-brightness LED lights that correspond to each circuit function. Simply turn on the lights to clearly read the display status and easily identify specific wiring issues.
Durable Construction: This trailer harness tester built with rugged nylon housing that resists rust and corrosion. Features tin-plated copper terminals for reliable conductivity and includes a protective rubber cover for the female connector.
Compact & Portable: The compact design of this trailer light circuit tester makes it easy to carry and store in a glove box, tool kit, or storage compartment, making it ready to use wherever you go.