I have a 2016 nv1500 my company is installing 7 pin trailer breaks and I found the plug and play under the dash and hooked it up. But the blue wire that connects under the dash I can’t find it in the back nor any plugs other than the lights. Any ideas checked under van and there is nuthing in the back the only thing I can find is the harness for the tail lights and back doors it is inside of van.