Truck won't start

[Derek05]

First off i have an 05 duramax, stock except for the stereo and wheels/tires. The truck has been sitting for a few months and the batteries died on me. I have replaced both batteries and am having a problem with the truck not starting. I have been on this site most of the last two days searching for solutions and it seems others have had the same problem but i cannot seem to get any of the other solutions to work out for me.
The security light comes on when i turn the key but quickly goes off. It comes on after i try to start the truck but then goes off pretty quickly again. I dont have much knowledge of diesels unfortunatelly so i am turning to ya'll for help.

[conway]

This maybe silly as I am not a diesel expert also but go to the fuel filter assembly and press the buttton on the top of the assembly. If it goes down easily you have some air in your fuel line and the diesel is not getting to the cylinders (You then need to prime/bleed it). If it is hard, as it should be, then you have ruled out one possibility.

[chessy56]

Do the glow plugs cycle? If so, what happens when you start cranking? I've had the fuel filter head go bad on me as it has a check valve in it that prevents the fuel from draining back into the tank once you shut off the engine. Unless the fuel line to the pump is primed, it won't start. Same thing happened to me after my last fuel filter change- I had to do a bit more priming (you can crack the bleeder screw on the top of the filter head to help releave some trapped air). After the filter change, mine cranked but didn't fire up. Pumped the primer button several more times until it felt "firm"- started no problem.

Hope you're not getting the SEZ light (check engine). Also hope your check valves aren't bad in the filter head- that'll set you back about $500 for the filter head/filter/water sensor assembly (only way I found that they were sold). Easy enough to install however. Hope I've added something of benefit.
Chessy56
2001 K2500HD, LB7, 214K miles (injectors replaced @ 175K miles)

[DmaxMaverick]

Forget about the glow plugs, for now. The truck will start without them down to way colder than now. I did some testing a couple years ago on a trip up north, with a few cold starts at well below freezing, with the coldest at about -10°F. Rough idle at first, but it started with no problem, every time.