Car wiring diagrams: Bmw Serpentine Belt Diagram, wiring diagram, wire wiring harness, schematic circuit diagram, wiring diagran, wireing diagram, wirring diagram, wiring daigram, wiring diagrams. Select model from list of vehicles manufactured by BMW. BMW I BMW I BMW I BMW IS BMW TI BMW I BMW CI BMW I BMW IS.Serpentine Belt using a Tensioner. The Serpentine Belt Diagram to the right uses a tensioner and is from a .L big block. Notice that the smooth side of the belt is .Serpentine belts, belt diagrams, belt tensioners, removal tools, replacement cost, instruction on changing and checking and a support forum if you need any help at all..