Dilbert, I'm following your post as well. I have the same problem. With shore power - everything works. Unplug and nothing. I have a new battery (tested good), checked all inside fuses, checked the in-line fuse coming off the battery, and all relay posts on top of the battery show 12 volts. Just bought the pup used (2 year old HW276 popup) - it had the problem when I bought it and I assumed it was the battery. I see you fixed your problem by replacing the in line fuse - guess my problem is a little deeper.