miloslouis,
Really don't think he found the problem but is creating a problem - using the the key cycling trick to milk more run time only further discharges an already sick battery. By taking a hot battery off the charger, makes the flat line come faster for the battery & truck and is sounded like he does this repeatedly throughout the day. The doctor says only take one charge cycle a day more than will be harmful - like you (truck & battery)will die.