Batboard

Hello I just bought a Whelen 12v Power Airhorn Plus PA . I am looking to install it in a 2005 ford explorer. Looking to see if anyone can help me find the horn relay wire to hook up the airhorn directly to the ford horn. I am having trouble locating the relay. thank you

The safest way is to go outside to between the horns and the horn relay - tapping inside the vehicle is very touchy as most lines are now multiplexed and can shut down other functions....