They have it on the inlet manifold. If you look under the bonette on the right hand side of the radiator as you look at it there should be 2 wires coming from that area to a silver block with a big black pipe coming off it to the intercooler , you may have to remove the air intake to see it. It has a number of blade type wires inside . Its these that heat up when you use the pre heater. The wires on the out side could be loose this normally causes the pre heat light to flash.driver1919 said:Had to call out R A C other day non starter was battery but he also told me i needed to replace the Glow plugs took it to garage to get price he told me that my 2.9 sdona does not have glow plugs but something on manafold does anyone know if this is right ?????