I was driving a few days ago and without warning the truck just shut off and now its completly dead . the battery is fine but no lights or anything. is this a computer problem?

First thing I'd try is to shake the battery terminals/posts. Not uncommon for the factory Delco battery to have a post break off. Sounds crazy, but it happens more often than you'd think. Then try to pull on the mid sized power wires from the battery cables, they have fusible wire lengths in a different colored section of the wire and they can burn in two. The wire will stretch out if it is burned in two.

First thing I'd try is to shake the battery terminals/posts. Not uncommon for the factory Delco battery to have a post break off. Sounds crazy, but it happens more often than you'd think. Then try to pull on the mid sized power wires from the battery cables, they have fusible wire lengths in a different colored section of the wire and they can burn in two. The wire will stretch out if it is burned in two.
Thanks but that wasnt it Ed

did you take a test light and check all the fuses?

Two words, check fuses. Since your truck shut down all of a sudden, check the fuses that are under the hood first. Sounds like you blew a large fuse. The other one is add some fuel. I actually had this problem where the truck shutdown, but in reality it was out of fuel even though it was showing a quarter tank!

Two words, check fuses. Since your truck shut down all of a sudden, check the fuses that are under the hood first. Sounds like you blew a large fuse. The other one is add some fuel. I actually had this problem where the truck shutdown, but in reality it was out of fuel even though it was showing a quarter tank!
Thanks but its not the fuses

I'd next suggest the ignition switch, on the steering column down under the dash. Might bang around on it some while you cycle the key and see if you get any response.

i was having same problem, cables were'nt connected well enough, when i eventually bumped a curb just right, no more power.