I know some of you have installed a 12VDC TV so you can watch on the hook. It occurred to me, that if you are hooked to shore power or running the gen, you might prefer to have the TV run off of that instead. Our fridges are smart enough to switch over to AC when we plug in, so I figured there must be a way add the same functionality to my TV. I don't know how many folks around here can read a schematic, but here's an auto-power circuit I cooked up. The relay has normally closed contacts which means when shore or gen power is applied, the contacts open up. This disconnects the 12vdc lighter socket from the house bank. At the same time, the wall-wart gets 120vac from shore or gen and supplies +12V to the TV. When shore power is removed, the relay contacts close, supplying +12vdc from the house bank to the lighter socket. The diode isolates house power from the wall wart. Note, this same kind of setup can be used for other 12v devices, such as a DVD player, DVR, etc. Just make up multiple DC harnesses and and use a multi-outlet lighter socket.