We went camping for 11 days and after getting to the camping spot and unhooking the truck did not move for the 11 day period but 2 days before leaving camp to come home i went to start the truck to get it lined up with the hitch and both batteries were dead found no lights left on only thing that was in the on position was the 4x4 switch but that sould not make the batteries go dead put a charger on the batteries and got the truck started but noticed that the mil light was on so i drove the truck for about 20 miles to charge the batteries a little bit more than what the charger did sunday morning when i hooked the truck to the trailer the mil light was out what can i look for that might cause both batteries to go dead before i take it to the dealer