Greetings and question

Our F-150 turns on all of the trailer lights for about 15-20 seconds when the umbilical is first connected. I usually do a quick walk-around to check them at that time. We still do the turn signal brake light check anyway, but the initial sanity check at least lets you know you're "connected".

When I have the headlight switch in full auto, it will also turn on the DRL if you are in a forward gear. If the windshield wipers are on, or if the ambient light is low enough, it will also turn on all the lights. As previously mentioned, DRL do _NOT_ turn on the rear/trailer lights. In fact, with DRL, the headlights are turned on, but at a lower intensity. We find it a good safety measure to switch to full on when pulling the pod just to get the aft lights turned on. For me, I just check the little fender LEDs when we get underway.

On our previous vehicle that had DRL, when it was set to automatic, the rest of the lights came on and the headlights went to full power when it got dark or when the windshield wipers were on. Our Frontier does not have DRL. I would prefer to have them but according to the owner's manual, they were a Canada only option for the 2010 model year. I don't know about other model years.

In most vehicles with daytime running lights only the headlights operate.

Welcome kaubey.  It's a good idea to make sure all your lights are working before you take off.  We made up a little check list that we always use before moving the trailer.  It's got all the hitch stuff, door step, lights, and all the other things you want to make sure are working or secured before you go.  In the confusion of starting out a trip, it's easy to forget even obvious things like closing the door.  I know, I've forgotten too many things and felt really silly. 

I guess I don't think about it much, as the truck turns the lights on & off without my intervention. Likewise, the trailer lights come on with the truck (when they're connected of course).