Glow Plug Light

[crowswagon]

Hi all,
I've been trying to get to the root of a hard starting / slow
starting problem for a while now.
I replaced all battery cables, including the crossover, starter, and the lead
to the alternator.
One thing I have noticed lately, is the glow plug light will remain dimly
lit after the engine has started and while it is running, and will only
fully go out after the engine has been shut off.
Is this an indication of a fault in the glow system?
Are the plugs remaining on, or is there a small amount of current
being sent to the plugs?
How do I check if the plugs are working correctly?
Thanks,
....Warne

[trbankii]

I had some similar symptoms when my glow plug relay went bad. Replacing it cured my hard starting issues.

[DennisG01]

There's quite a few posts (and by quite a few, I mean A LOT) about glow plugs - if you do a search you'll find a lot of reading material, including how to properly check to see if your plugs are OK.
However, to see if if the plugs are getting power after the engine starts - just put a voltmeter or test light on the glow plugs (or directly on the GP relay terminal that goes to the plugs) while the engine is running. There should be no voltage there after truck starts (except maybe for a few seconds depending on ambient temp).