On a previous post you were looking for a brake controller and harness to connect to your factory installed connector. You mentioned you got what you needed from eTrailer. I assume you have installed this. Just to isolate the controller, unplug it from under your dash to ensure it is not the issue. I should not be but if for some reason eTrailer hooked you up with the wrong harness there might? be an issue.
If that is not the problem disconnect the plug, replace the fuse and then use a VOM to ensue you have 12v on the truck side and 12v on the trailer side. If either connector does not measure any voltage you can then check the resistance with the ohm meter to see if you have a short. This could be mis-leading if you have any voltage at all on the pins. Use the reference Trailer Wiring Diagrams | etrailer.com
Also as posted previous, disconnect the trailer battery to see if it is an issue. Do the trailer lights and other DC stuff on the trailer work? It would seem battery is connected correctly, especially if the radio works.