Not sure if this helps or not but maybe something is keeping the can-bus system "awake" and drawing too much current. It may be something as simple as a switch on the tailgate latch
I had a similar problem on my Honda. One of the switches on the tailgate latch was not closing and keeping the body control computer "awake" and drawing too much current. It took several days for the battery to die...
"It's not the critic who counts..." T. Roosevelt
Last edited by MicroMark; 03-27-2017 at 06:19 PM.