I installed mine SAT afternoon, Works great.
I used a bosh relay I had laying around and tapped into the postive wire going to the fuse box under the hood. That was much easier than going directly to the hidden battery (used in line fuse as well). I didnt want to mess up the factory wiring by overloading it (or the oem fuse). But I used the factory horn wire as the trigger so no seperate button to push in a panic.
Its Super loud!
2017 Axis / 25.4: Big Foot Levelers, Aims 1200 Watt inverter, Ceramic Window Tint, Full River AGM 6V batteries, Front Hellwig Sway bar / Rear Track Arm, Safe T Plus Steering Stabilizer, PD 4655 converter, Hard Wired Surge Guard, WEboost + WiFi Ranger, LED Headlights/Driving lights, TPMS, Surge tank, Tornado flush, Viair Compressor