Hello colleagues. I have a factory radio RD4 RN1 with bluetooth auto Berlingo III 2009. I bought a pocket, a factory shelf under the radio with USB AUX and I have a problem with the connection. There is such a gray plug there. Does anyone have any schematic? I suspect that in section C of the radio cube some contacts are responsible for AUX on the cable, but after activating Lexia, I would like to use USB.
Thank you for your answer 