Gen 2 12v AUX power How???

What is the best way to wire up 12V Aux power to a 7 plug for charging RV Batteries? Do you fuse it straight of the battery? or Do you set it up to turn off with the ignition? I would like to here how others have done this.

 

My choice is to use a non-used plug port (you may have one) and wire direct from the battery to the 7wire plug. You already (or should have) a good ground wire installed so that's mute. On the trailer side, run a wire from the same port to your load...easy as pie. As for fusing, I'd use it on the trailer side. The truck is already wired "hot" for all the lights on the plug and don't cause a problem. This way, if your fuse or breaker (my choice) trips, you know it's on the trailer side.

If you want to control it from the ignition switch, I'd use a relay to transfer the power. Key on...relay live, key off...relay off.

 

Since I have the tow package 12v is already there and factory setup is to have the 12v off when the truck isn't running. Otherwise you run the risk of draining you truck battery if you leave the trailer hooked up and your trailer battery is going bad. My wife had our Chevy set up to have 12v to the trailer plug all the time because her horse trailer doesn't have a battery and she want's to use the aux lights on the trailer when the trucks not running.

 

Thanks for the advice guys I like the relay idea. I wired my nieces horse trailer like your wife's goober. But I agree not a good idea with a camper battery