Larry Connally

I have a trailer that I have towed for over 7 years with my 2006 duramax. I hooked new 2019 duramax to it and the only lights that work are hazards and park lights. Brakes don’t work hooked up to the 2019 either. Power at plug. Hooked back up to the 2006 and everything works. Hooked up to my buddies 2012 Ram and everything worked. Any ideas? thanks