Good day, I have a 320 D BMW in the mornings it struggle to start, I have to try 2 times but takes long to get to start. So there were 3 things that they say can be problem - the diesel pump - relay - found one behind the clove box is there another one? We replace the diesel filters or something. NOw it can only be the globe plugs - where can I find a diagram for this model? Can it be something else?
You can check the glow plugs with a multi meter, first ensure that each plug is getting powered up on the glow cycle, test this with a volt meter, if this is ok, disconnect each plug from the power source and test continuity between the thread wher the power wire attaches to the glow plug body, if it is an open circuit, the plug is faulty, if one or more plugs are faulty, fit a full set.