After the non-starting episode on Thusday, I thought I had it sussed when there was no output from the relay, so I got it started using a jump lead direct from the battery to the glow plugs. Anyway, got hold of a new glowplug relay yesterday, and got no output at all from it. So something else is going wrong somewhere. The old one may have been faulty(and may not)), but this is what happened when checked - input voltage was fine, no output when ignition on. But, the relay does trip, then open again after 20 or so seconds.Just as it should. The fault here is that when the relay shuts, the input voltage goes down to 0, until when it reopens, then it goes back to 12v. So, where is this power going to? The new relay can be heard clicking, so presumably is working as it should, but there seems to be no output from it - certainly the needle does not even flicker when ignition is turned on.
Also, I havent found an online schematic for the wiring diagram, there are 6 connectors on the relay - 2 main power connectors, and 4 smaller size ones, presumably 2 of these are for tripping the relay, what are the other 2 for?
Thanks for any thoughts. Alan.