In order to install a brake controller on your 2015 International 7400, you would need to hardwire one into the vehicle's wiring harness as we do not have a plug-in adapter for you. I recommend using the Tekonsha Prodigy P2 Trailer Brake Controller part # 90885. The Tekonsha Prodigy P2 comes with a pigtail adapter that has 4 wires that will need to be ran for installation.
Red Wire: Stop Light Switch (Cold Side of Brake Pedal)
White Wire: Ground
Blue Wire: Brake Output
Black Wire:... view full answer...