HELP, DOES ANY MENBERS KNOW WHERE I CAN OBTAIN A WIRING DIAGRAM FOR MY SL./91 AND FOR A 96 S CLASS, REASON FOR THIS ,MY SPEEDO HAS STOP WORKING AND IVE OBTAIN ONE FROM A 96 S CLASS, ALL THE DIALS ARE THE SAME,AND THE WIRES LOOK THE SAME, DOES ANY KNOW IF THESE PARTS ARE INTERCHANGEABLE?:confused: