I had a few faulty glow plugs a year or so a go. I changed these and then cleared the OBDII fault codes. All was OK until about 2 months ago when another GP faulted so I changed this GP but it did not fix the issue. (I have checked the replacement GP and it works fine) Does anyone know what else can be done to correct it. I'll put a multimeter on the wire tomorrow to make sure I have power. Are there any other things I should be looking for or any other tricks I can do to fix the problem with GP #2?