I was scratching my head for a bit trying to find a random battery drain in a truck that has keyless entry .. Out of sheer luck I happened to be watching the data stream on my scan tool right at the point of the body control module time out and saw it come back from dormant..
Turns out the battery in the key fob was dying and sending mixed signals to the truck if it was close enough for the truck to pick it up. When I talked to the customer he said it made perfect sense because the times the truck would be dead was when he left the keys in the ignition and use the keyless entry to open the truck.
I kind of wish he would have shared that little tidbit of info before I wasted my day trying to figure what was causing the draw on it.
Anyways .. I hope this may keep someone else from wasting their day on something so stupid.

 

And when you ask those little important questions they look at you like you are an idiot.
I had a 08 6.4 ford that had water in the oil.Found a pinhole in the timing cover at the waterpump.Pull the waterpump and look for pitting in the aluminuim in the center of the housing.Just behind that is the camshaft and oil.Before replacing oil cooler.

 

Wow good info, my battery is low on mine. Changint that sucker haha!

 

440mark front covers are common in the 6.4, also check your thermostats housing ive had those come apart as well, how bad was the base filled with sludge, , my last oe had chewed apart all the rocker boxes