the fuel lines to the injectors were noy tight enough.got that tightned.but like 2days later i had the same problem in the morning.it wouldnt start.so i plugged it in an it fired right up bout an hour later.is there like heater deals on this truck that could stop keeping it heated>

 

it sounds like injectors to me usually a no start at 40 degress and under is a good indication, oh and never ever use starting fluid on these trucks

 

If the lines to the injectors were loose, you'd have fuel everywhere. those are HIGH pressure lines.
Id be leaning towards bad injectors, does it smoke while turning over?
What about smoke when it starts?
There are grid heaters in the intake, its like the heating elements in a toaster, its in the intake horn, above the head. should be two large gauge wires running there. Thats not likely your problem. Its been below 0 F and my truck will start with out being plugged in.
Id say you have leaking injectors.

 

the fuel lines to the injectors were noy tight enough.got that tightned.but like 2days later i had the same problem in the morning.it wouldnt start.so i plugged it in an it fired right up bout an hour later.is there like heater deals on this truck that could stop keeping it heated>

 

My 07 dodge 6.7 ran fine till i stopped to get a pop..came back out it started and died..now just cranks will not start cost me 100.00 bucks to get 10 miles towed...

 

Could be numerous things, but, I have an 03 also with, at the time they went bad 240,000 miles, and it was the injectors. Would turn over till the battery died unless you spayed it with starter fluid. Once it was running, ran like nothin was wrong. Replaces all the injectors, fires right up.