Quote Originally Posted by C-MAN View Post
Also, crawl under your truck and check your central starter lug and see if it is loose; they corrode and or burn out over time from so many starts and sit in there almost unconnected and will always slow crank as if the batteries are weak even with new batteries.

Still, the juice from jumper cables might cause it to cross enough direct power to let it start.

Ask me how I know, LOL.
I am going to be doing some more troubleshooting today.

I will check it out

Thanks!