Ok guys I need some help here because I am totally lost. Went to leave work one night truck wouldn't start. Didnt want to crank. It barely turned over and was struggling to crank.While it did crank the lights inside were flickering and the gauges were going back and forth. Then starter just started clicking and truck wouldn't even turn over. Short end of the a long story is I have replaced starter, alternator and batteries so far. Truck still seems like it is struggling to start. When it cranks it does not seem to be cranking very fast. The best way to describe the way it is cranking would be if you had week batteries. As I was saying before starter alternator and batteries are all new so i know it is not them. Does anyone have any ideas what could possible be going on? Thanks for the help.