Allows one person to quickly test all towing output functions of their vehicle– 12V Power & Ground, Turn Signals, Brake Lights, Running Lights, Backup Lights, and Trailer Electric Brakes – while never leaving the towing vehicle’s driver seat. The Test Box is a rugged professional quality diagnostic tool machined and assembled here in the USA. It is constructed of a powder coated die-cast aluminum box with long lasting ¾” LED lights, and a standard 7-way plug with a 5 ft cord to reach the side of your vehicle for easy viewing from the driver’s seat.

Our mptb201 comes with a built in female output 7 way plug, which allows the trailer to be plugged in, and the box to act as a pass through as well, to help diagnose where faulty connections may reside in the truck/trailer system.