MY 6.0 started up fine, then one day it ran the gloplug cycle then when i went to crank the engine, i lost all power and the batteries were drained when i checked them with the volt meter...thinking it might be a grounded positive cable, any other ideas on what might cause this issue?

 

Shorted cell comes to mind. Fix it before it takes your ficm out.

 

what do you mean shorted cell?

 

One of the batteries may have a shorted cell dragging both of them down. You need to totally seperate the batteries, charge them and have them load tested, once again seperately. If one shows bad replace them both.

 

A bad alternator possible

did the starter even engage

did all the dash lights freakout

Electrical issues suck