Trying to find a wiring diagram for the factory brake controller harness from plug under the center of the dashboard to the 7 way connector at the rear bumper. Have an open somewhere on the modulated hot wire that actually drives the electric trailer brakes ("blue wire"). Trying to find out if there are any connectors, breakers, fusible links (etc) and where they may be. Have checked the connectors at the rear just forward of the 7 way plug... Thanks!