Review on 💡 Efficiently Test Circuits with POLLAK (12741EV 7-Way Circuit Tester) by Paul Dahl

Purchased for use on a Mercedes GLS 450 with a factory fitted 7 pin plug. The top row of LEDs only blinks and the product does not work properly. There were no instructions with the product. Manufacturer contacted for additional support. Pollack responded with a video from the E-Trailer website. The video offered no further diagnosis. I took the car to the dealer for checking, pin 7 works fine. According to Mercedes, LED warning lights do not work on these types of vehicles.