I have a 2007 NH TC-30. It has been a great machine but has developed a very trying issue! When shut off, the battery slowly drains until, after anything longer than 3 days, it does not have enough juice to crank. It is easy to jump and runs fine then. And if it has run long enough to recharge the battery, I can shut it off and let it sit for 3 days BUT no longer! The 15 amp fuse, when pulled, stops it. But I don't know how to trouble shoot to figure out what is in that circuit that is causing the phantom drain. Any ideas?