lights on trailer on when driving

Chad/Jen wrote:
When bringing my trailer home over the weekend I noticed that the lights to my truck ('14 Chevy Silverado) were on (not just the DRLs but the actual headlights and taillights). I have the light switch set to "Auto" so I don't have to worry about them. I noticed when I looked in the mirror that the marker lights for the trailer weren't on. I think (but don't remember for sure) that in the past the lights for the trailer have come on when the ones for the truck did, even with the "Auto" setting on. I turned the knob to turn the lights on the old fashioned way and the ones for the trailer came on. Shouldn't the lights for the trailer be when the truck's are, even if the truck's selector is on Auto, or am I missing something?

on my 04.5 the trailer running lights only come on when the headlights are ON. not when just DRL are on. trailer running lights are hooked to the headlight circuit on the TV. So, in Auto mode if all that is on is the DRL, then the trailer running lights won't be on. when the truck headlights come on the trailer running lights should come on.

That's the way my 04.5 worked and my 2015.5 duramax as well.