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jor · Mar 2nd, 2008, 15:49

As per Craig's post the usual culprit is the glow plug. I changed mine a year ago buying the cheapest type (non branded) and guess what - they have just needed replacing again. TFB suggests checking the resistance between the connector part and earth, having removed the copper strip that connects them. I could not get consistent values (above 4ohm is bad) and wasn't certain I was doing it right, so I took out the 4 easily accessible ones and connected them to a battery, one at a time. Working ones definitely will light so watch out for the carpet. None of them did so they have been replaced with 4 Bosch ones. I'm sure the other 2 are also kaput, but it starts well enough so will do the others 'sometime'.
The engine will start on compression alone when the temp is somewhere around 35C.
I know engines will start on 3 functional plugs - as the first time I did mine I forgot to connect the copper strip to the inner 3 plugs, so if you find that the ones you test are working then the trouble lies elsewhere. The fact that the light is not coming on is a bit suspicious of an electrical rather than a plug problem. There is a diagram of the glow plug circuit on Ross Winberg's volvoturbodiesel.blogspot.com, however I can report that I know nothing about electricity so to me it's meaningless. However if the plugs work and you can get hold of a working relay and the thing still won't start then by exclusion it's got to be the switch that's faulty. The one part of the relay that's easy to look at is the fuse visible at the bottom after you undo two nuts and the connectors.
My guess is that the switch is bust.

john

Mar 2nd, 2008, 15:49	#4
jor VOC 20573 Last Online: Jul 10th, 2023 22:14 Join Date: Mar 2007 Location: wembley	As per Craig's post the usual culprit is the glow plug. I changed mine a year ago buying the cheapest type (non branded) and guess what - they have just needed replacing again. TFB suggests checking the resistance between the connector part and earth, having removed the copper strip that connects them. I could not get consistent values (above 4ohm is bad) and wasn't certain I was doing it right, so I took out the 4 easily accessible ones and connected them to a battery, one at a time. Working ones definitely will light so watch out for the carpet. None of them did so they have been replaced with 4 Bosch ones. I'm sure the other 2 are also kaput, but it starts well enough so will do the others 'sometime'. The engine will start on compression alone when the temp is somewhere around 35C. I know engines will start on 3 functional plugs - as the first time I did mine I forgot to connect the copper strip to the inner 3 plugs, so if you find that the ones you test are working then the trouble lies elsewhere. The fact that the light is not coming on is a bit suspicious of an electrical rather than a plug problem. There is a diagram of the glow plug circuit on Ross Winberg's volvoturbodiesel.blogspot.com, however I can report that I know nothing about electricity so to me it's meaningless. However if the plugs work and you can get hold of a working relay and the thing still won't start then by exclusion it's got to be the switch that's faulty. The one part of the relay that's easy to look at is the fuse visible at the bottom after you undo two nuts and the connectors. My guess is that the switch is bust. john Last edited by jor; Mar 2nd, 2008 at 16:02.