Why can't i get anything done?

[72gmcshorty]

I fixed my headlight problem. It seems that the brake light switch was not being fully depressed enough to stop allowing current to flow to my steering column. So being as happy as a pig in sh$t i go to start my truck and now i'm not getting any juice to the starter. The truck has started before I fixed this headlight problem and now I'm getting nothing. I'm going crazy. I wonder if my battery is dead. If it reads 12V on my tester it should be able to turn the starter right?