GM-GMC: gmc 3500 6.0 vortec, gmc 3500, ooil

Question
the truck ran out of gas ,so I put more gas in it ,so when I go to try to start it everything works until I turn the key all the way and I get absolutely nothing!

Answer
ok first question for you? when you turn the key all the way forward do the lights on the dash go out?

if so its most likely your starter wiggle the connection and try again or hit the starter with something like a wrench or hammer not hard just tap it enough to jar it loose

if you turn the key and all the lights stay on but no fire its probably your battery connection maybe loose see if you can move them on the battery and if so then try to start it again.. this might also cause the lights to go out or dim very low

one other thing is your ignition ooil and relay fuses under the dash check them