Kyle,
well let's make this simple
fuse F6 supplies main battery power to the truck control wiring and components.
ecm, most sensors, transmission solenoids and sensors.
Like some other lifts i believe these systems have to have battery power full time to the ecm which is why when you unplug a sensor even if the truck isn't running it may set a code. Also why they say to disconnect the battery for a couple minutes to get the ecm to reset the stored codes if you don't have pc service tool available to do it by pc.
I would first check the obvious, external devices added on if any, then go from there. Alternator, then other sensors.
How much of a drain is there?