Ran autoscan on vagcom and showed 4 glow plugs faulty which seemed strange for all 4 to be faulty.What is the best way to check them? What i have done is remove all 4 glow plugs and tested them by connecting 12v power direct to them (12v+ to tip of plug and 12v- to body of plug)should this cause the glow plug to glow orange ? cos none of them did or is this the wrong way to check them?
John
John