Not starting, glow plug issue?

[therealchrisgray]

Hi all, greetings from the Outer Hebrides - where my 1.9 diesel van has decided not to start when cold! (ie every day)

I drove it last week no problem, but when I came to go home it just cranked over with no sign of any combustion. It usually starts first time, so this was worrying.

After enough attempts that I was starting to fret about draining the battery, it finally caught and blew a big cloud of white smoke (vapour) out the exhaust before settling down to running normally. Came back to it a few days later, it wouldn't start and I didn't have time to fiddle with it so I left it til today.

It seems I have fuel, compression, and power in the battery, so I did a few experiments:
- remove a glow plug and connect directly to battery for a few seconds, it got very hot
- multimeter on the (disconnected) power cable to the glow plugs indicates no current flowing on key turn
- a wire from the battery to the glow plugs for a few seconds resulted in it starting immediately I turned the key
- once the engine was hot I turned it off and it restarted easily

So I'm 95% sure I'm not getting power to the glow plugs when I turn the key, although the orange light does come on for ten seconds or longer. And I know nothing about vehicle electrics.

Can anyone advise on how I would go about tracing the fault, as a beginner?

[hotpod]

There should be a glow plug relay somewhere. Mine is in the engine bay in a black plastic box on the left hand side wall.
I would start there.
At the start of your post I was suspecting air in the fuel line but since you tried the glow plug tests then I would first check you are getting ignition power to the relay first. And firt find your relay. Trace the cable back from the glow plugs and you should find it.

[therealchrisgray]

At the start of your post I was suspecting air in the fuel line

Yeah, that caught me last year!

[mioba]

GP light should go off very quick this time of year.

Have you checked the GP strip fuse in the black
box off engine bay. Always have a few spare.

[therealchrisgray]

There should be a glow plug relay somewhere. Mine is in the engine bay in a black plastic box on the left hand side wall.

Found it!

Can anyone advise before I buy a new relay? Have I forgotten anything?

This is all a bit hit and miss because I'm on my own and don't have anybody to turn the key for me. But since the orange light stays on for at least 10 seconds, I have time to turn the key and then run to the back of the van to check stuff, but here goes:

I checked that the relay is getting battery power, at one of the two terminals beneath it. But no power out to the glow plugs, even with the ignition key on.

I double checked this by connecting a wire directly from the output terminal to the glow plug bar and trying to start the van. No glow!

I also used the audio recorder on my phone to check whether the relay solenoid is firing, I left it next to the relay while I went and turned the key a few times, and I could hear it clicking in the recording.

Then I removed the relay and poked around with a multimeter, and got a 12-volt reading in the slots with the key turned. So I think this confirms I'm getting power to the relay from the key?

The AI tells me the internal contacts in the relay are probably burnt out. But I wanted to check with some actual humans that know what they're talking about!

Is there anything else I need to check? Other potential issues I haven't considered?

Thanks all