Running lights gone too !
For a moment I though you had solve my problem. Last night, on my way home, people on the freeway were passing me flashin their lights. I discovered all my back running lights were shut down.
I read your post and found the fuse panel but all the fuses are good. With a voltmeter I was able to find that the power is going out of the fuse panel but not reaching the lights.
I supposed the tow hitch and the tow light connection are from Forest River or installed by the previous owner. Anyway, I do have power at that connector.
What I think is that a wire went loose in the connection (real running lights and trailer running lights) I can see the connection, looks likes a big amount of electrical tape but now, the only way to reach it and work on it is to remove the rear bumper to get to it.
Good thing is that we have a wonderful end of september in Montreal, 23 Celcius (75 Farenheit) at 5h00 PM.