Photomike wrote:
Cannot see the camper draining the truck either. I also would say unplug truck and camper and let it sit and see what happens. Could be a huge phantom draw in the truck.
+1 It doesn't make sense for the camper to drain the truck without also draining the camper battery.
I had a problem where my truck battery was going dead. Camper was fine though. Took me a long time to find it. I had to put an ammeter in-line between the battery and power cable. I slowly went through each fuse one at a time to try and find the phantom draw. Have to be careful not to turn anything on as the ammeter could only handle a small draw without blowing its protection fuse.
Eventually found the MSD ignition box I added at one time was the culprit. I had accidentally pinched a wire when mounting the box. It had rubbed through the insulation just enough that it created a weak draw and would drain the battery after a week or two.
HTH,
-Eric