This is my first motorhome. I have been rv'ing for 8 years. I bought a class c Jayco Greyhawk and towing a Jeep Wrangler. I got a brake buddy with the setup and I don't think the dealer had it set ...
Although I no longer use a Buddy Brake, their technical phone support was fantastic. Give them a call and they will take all the time needed to trouble shoot your system. I now use the ReadyBrake, as I got tired to playing with the box.