3536C4-Pin Trailer Light Tester


4-pin Small Size Trailer Light Tester & Circuit Troubleshooter for US, Plug tester into vehicles 4-pin connector and operate vehicle's turn signals, lights and brakes. When there is power present, the green light will glow.


  • Fits 4-Pin Small Size Trailer Light Tester & Circuit Troubleshooter, Quickly and easily see if your trailer wiring is properly installed on your vehicle
  • No Batteries Required.
  • LED light Indication
  • Test right, left, turn, and brake lights for proper function.
  • Easy to carry, Compact Design Fits in your pocket


Simply plug it into the bumper connection or in-line between the tow vehicle and trailer, turn on the lights to be tested and check the LED lights on the tester. The correct LED will be illuminated if the power and ground wiring of the tow vehicle is functioning correctly.