Hi guys, I have a 2012 FX4 Supercrew and I am planning to add a set of train horns this week. However, I have a dumb question. Where/how do I tap into power on this truck? I need to power the compressor and I want this to be an ignition only source. I also will need to power the switch for the solenoid on the actual horn. This can be ignition only or constant on. Doesn't matter as much. I am trying to figure out is it smarter to splice into a wire under the dash? Tap something under the hood? If so, what do you suggest I tap into? I have heard some people talk about making use of unused fuse spaces, but how hard is that? Do they have power going to them or do I need to modify the fuse panel? I certainly appreciate any advice you can give.

The last time I did anything electrical was on an older truck and it seems like there was a lot more room to work.