Cigarette lighter wiring

Sorry, Eric. I would not tap into the hot ignition feed. It may be supplied from a fusible link which could be overloaded and fail with a load he plugs into the socket leaving him stranded with an expensive repair. For his needs, I would suggest getting as directly to the battery as possible and using an inline fuse suitable for the wiring and lighter sockets..... The fuse rating should not exceed the rating of the wiring or a single socket whichever is lower. For a 20A fuse, you should be using at least a 12AWG feed. A 14AWG feed should not be fused higher than 15A. If the circuit should be cold when the vehicle is not running, a relay in the circuit activated from the ignition is the way to go.