Tests 4-way flat connection for tail lights, brake lights and turn signals to note what is wrong with the cable on the car side and without the need of having a spotter
Easy to read. Towing tester is going to be left LED is tail/brakes, middle LED is left turn signal and the right LED is right turn signal. To be extra helpful, this is with the LEDs light up.
You need to turn on signals, apply brakes, etc. The device simply acts as a trailer light system that you know is functioning properly, allowing you to verify vehicle system is good
A good tool when trouble shooting a none working light. If these lights come on as expected, then the issue is downstream of your vehicle wiring
This is very handy. Can keep it in your glove compartment. Or carry way it to trailer like U-Haul trailer, truck like Ford GMC Dodge
Helpful when you want to test your connection without having to hook up a trailer. It also helps eliminate your vehicle from the equation when your trailer lights aren't working.