Not sure what's going on? Battery, starter? Idk

I had same problem for years until it went all the way out, and I had to fix it, maybe I can help 70â„… of the 261 people on here. There is a small signal wire at the solenoid on starter that I traced it to, where it was crimped to clip that a small nut secured to solenoid was corroded green and not making a good connection. I cut off about 3in and soldered new 10 guage wire and a new flat wire connector in place and like brand new, no more problems. I have pict. If there's anyway I can send to people. My wire was purple on my 2005 Silverado Z71. I did get really tired of slamming doors and turning key switch on and off and moving gear shift from park to neutral trying to get it to crank. Good luck to everyone, hope this helps.

to the right of this page HIGHLIGHTED IN BLUE under problems,click on that and read.you're not the only one having that problem.if you find out what's causing it,maybe you can reply to the other (reported) 240 folks,and tell them how to fix it,cause they can't find the problem.check the ground wire under the battery tray,see if it's ok.