Parasitic drag on battery....Need some help.
 

Hey all, got a 2012 fx4 5.0 litre with some troubles. Battery died on me a while back and seemed to be weak so i was considering a new one anyway and changed it. Day or so later it my truck would not start. Did some trouble shooting and found a circuit running thats connected to the PCM relay, i can hear something running so i found what circuit it was and removes the relay and noise goes away. I am hearing the sound around the transmission area mostly, sounds like a electric pump or fan running very faint but its there. Seems lile its on top of the transmission too but not sure . I was told maybe the airbag module which is in that area ..but need some help in locating the issue. Any ideas?

Any luck with this? I am having the same issue on my 2014 5.0.

Maybe try taking off the negative cable for 40 min or so, (to drain all stored power) so it will reset the system. Maybe a malfunction in a module its trying to run something with the truck off.

Best of luck to you