Every now and then my truck doesnt start. When i turn the key lights on dash come on but no crank. This happens randomly sometimes i can go for a couple weeks no problemthen all of a sudden it just doesnt crank. I usually get a jump and it starts up fine. Sometimes it starts imidatley sometimes it takes a sec to charge up. I know its not the battery necause i already replaced it. Im thinking it could be the ignition switch?

 

if you have to jump it off it could be your alternator is not charging right,,,drive it to your local autozone and have then check you voltage output from the alternator

 

In many cases the symptoms you describe can be traced to bad connections either at the battery, the starter or ground. Its an easy and cheap fix to remove each one clean the surfaces and re-tighten and could eliminate the issue.

 

Check closely where the power cable attaches to the starter. It is a broad spade shaped connector with an angled part and a hole in it where it attaches. Mine was corroded and eventually failed at the bend in the metal cable connector.