Hello dear elk community, I am a short time owner of a SC901 and wanted to incorporate this into my 850er (94Bj). I have seen already open times 850er with this radio. The first fright: the original plugs were not on the wire harness of my vehicle. I then rearranged them and attached them to the wire harness of my 850er. Radio built in, code entered and see as it funzte. All functions are “operable”, the light goes, the CD 3x changer provides its service, the radio detects and stores transmitter and even the cassette part runs – so far as well ABER: from the loudspeakers comes no beeps! All cable assignments and connections again checked everything ok. on the occupancy place No. 6 of the small rectangle plug still hangs a thin yellow/black cable which however is not present on the cable tree of my 850er and according to the switching plan carries the name: Tachosignal. Who drives in his 850er such a radio and can help me further? Does anyone have a tip or an idea why I didn’t not fix it or LG did anything wrong?