Well ive got a flashing glow plugs light also. And it keeps flashing for quite a long time (30s or more, im not sure). Ive also got a P0380 relay fault so suspecting the control unit since the flashing is intermittent + the plugs were checked a couple of months ago (although that was about a month or so before all this began so its probably possible one or more of them died in the mean time). Is that plausible or are the plugs still the most likely suspect?
Also if i were to measure plugs resistances the procedure would be to first unplug the plugs connector off the control unit, then turn the key to MAR and then measure each connection's resistance inside the connector (with the other measuring point being the earth)?