Oil Cooler Replace
 

just replaced oil cooler with a remote unit. truck will not crank now. turned over at first with no crank. did not ever try to crank but would turn over. then stopped. drained oil and rotated by hand-no problem. putnin oil. no turn over again. what is the problem? how do i fix?

Oil pump must be working a little harder??

Batteries dead? Battery connections loose?

heads, gaskets, or injector cups. dunno which one yet but that it what it is narrowed down to so far. they all suck but it is what it is.