Features
Confirms proper vehicle and trailer electrical function
Tests 7-way for tail, brake, reverse, turn signals, brakes and auxiliary power
Features a label for each LED, indicating the intended function
Constructed with LED lights for long-lasting use
Rugged PVC plastic body is designed to be weather, corrosion and impact resistant
The nickel-plated copper pins are well conductive, wear and tear resistant
Even in the small details, this circuit tester stands out from the others.
Compatible with standard 7-way blade trailer sockets

Descriptions
Part of towing responsibly is making sure your trailer lights are working properly. Whether you have just installed a new vehicle-to-trailer wiring harness or are trying to locate the cause of an electrical problem, 7-Way connector tester is great for testing tail lights, turn signals, brake lights, ground connections and other electrical components on your trailer.
Directly plugging it into a connector socket on vehicle, it'll respond to the various electrical signals when you push the brake pedal, signals a turn, turn on the running lights, etc. When the socket is getting proper power, the tester's LEDs will light up corresponding to each wire in the connector. Testing your vehicle-side socket is essential after installing a new custom vehicle-to-trailer wiring harness and is highly recommended every time you hitch up to tow.
Also, if you are experiencing electrical problems with your trailer, tester will be able to tell you whether the problem is rooted in your vehicle's electrical system or if your trailer needs some rewiring.
Take this portable lightweight 7 way connector tester wherever you go and drive with confidence!!!

Function Codes
BU: Back up or reverse circuit center pole
RT: Right turn/brake
TM: Taillights
LT: Left turn/brake
BK: Brake controller output