Do glow plugs work when the dash light is lit?

[msjanket]

I have an LGT 16D Ford tractor, a great little number. It seems to start a bit balky. When I turn the key to the left, the dash light corresponding to glow plugs are lit. Does this mean the plugs are good and functional? Or, unrelated events?

 

[jaxs]

" Does this mean the plugs are good and functional? "
No,that only tell's you voltage is being sent to them (unless continuty is broke). Test each individually for amp draw,seldom do all go bad at once.