I got a professional to install a new power box in the camper. 120v. was disconnected and deep cycles in the camper disconnected, yet there was juice to the old box until I disconnected the TRUCK batteries! The new box went in and deep cycles connected but utilities inside the camper were not live until I reconnected the TRUCK batteries! Something is not right here. I had a battery isolator in a previous camper and assumed this did too, so that the truck batteries could never be drained. Apparently not now. What I see doesn't make sense. It seems the deep cycles do nothing. Can I get some suggestions for troubleshooting this? Thanks. Tom McCloud