The wiring harness if I'm not wrong is that black plastic "Y" shaped structure which is sitting on top of the area between the engine and the fuel injection set up. I suppose the structure is a heat insulator for wires within because of the tremendous heat generated by the engine in this area. This is a very hot engine. Mine is only 1800 or 1799cc and the heat is surprisingly hot only after a short trip. Maybe the coolant system is not sufficient or is designed for cooler countries like Germany/Europe and Canada where it would not overheat so easily. Our temp is now in the 30s and low 40s and my aux fans are working intermittently to help cool the engine. I can see the temp going beyond the usual 80 and down again when the fans go on.