10.1v @ Glowplug Rail

[Mark Elvin]

I'm getting a smoky start when cold, I measure 10.1v at the glowplug rail. this seams low to me.

The battery voltage when off load is 11.9-12.1v

[haydn callow]

That battery is almost flat....should read about 12.6 off load after sitting a couple of hours.
Could have something to do with your coolant alarm problems.

What does it read with engine running?

[Mark Elvin]

12.43v when off load

[haydn callow]

You have a problem....should read 14.2 approx ....... Check out the alternator....again 14.2 output at the alternator terminals

[rita]

10.1v at the glow plug rail is low the glow plug rating is 11 Volt.

12.43v when off load sounds ok.

[Mark Elvin]

When i say off load I mean engine off too.

[Simon Jones]

The voltage should stay on at the glowplug rail for a while after the light has gone out. If it drops out at the same time as the light goes off then something is not right. The usual test for glowplugs is to remove the rail and measure the resistance of each one in turn & compare to the recommended values.